Hacks at the Massachusetts Institute of Technology are practical jokes and pranks meant to prominently demonstrate technical aptitude and cleverness, or to commemorate popular culture and historical topics.      The pranks are anonymously installed at night by hackers, usually, but not exclusively undergraduate students. The actions of hackers are governed by an extensive and informal body of precedent, tradition, and ethics.  Hacks can occur anywhere across campus, or occasionally off campus; many make use of the iconic Great Dome,  Little Dome, Green Building tower,  or other prominent architectural features of the MIT campus. Well-known hacker alumni include Nobel Laureates Richard P. Feynman and George F. Smoot. In October 2009, US President Barack Obama made a humorous reference to the MIT hacking tradition during an on-campus speech about clean energy.
Although the practice is unsanctioned by the university, and students have sometimes been arraigned on trespassing charges for hacking,   hacks have substantial significance to MIT's history and student culture. Student bloggers working for the MIT Admissions Office have often written about MIT hacks, including those occurring during Campus Preview Weekend (CPW), an event welcoming admitted prospective freshman students. Alumni bloggers on the MIT Alumni Association website also report and document some of the more memorable hacks. Since the mid-1970s, the student-written guide How To Get Around MIT (HowToGAMIT) has included a chapter on hacking, and discusses history, hacker groups, ethics, safety tips, and risks of the activity.
For a decade, the MIT Museum included a "Hall of Hacks" featuring famous MIT hacks, but the section was closed in 2001, temporarily returning for a 2003 exhibition. In 2011, the display space was reallocated to the MIT 150 Exhibition, a year-long show commemorating MIT's 150th anniversary. Although hacks were not featured in the exhibit, certain student activities such as the Annual Baker House Piano Drop were featured in the exhibition. The Museum's extensive collection of hacker artifacts and documentation continues to be preserved and expanded, with a selection of larger relics from past hacks plus explanatory panels and plaques semi-permanently displayed inside the Stata Center. This mini-exhibit on hacks is located on the ground floor of the Stata Center, near the cafeteria at the southeastern end of the complex, and may be viewed by visitors during normal office hours.
Famous hacks include a weather balloon labeled "MIT" appearing at the 50-yard line at the Harvard/Yale football game in 1982, the placing of a campus police cruiser on the roof of the Great Dome, converting the Great Dome into R2-D2 or a large yellow ring to acknowledge the release of Star Wars Episode I and Lord of the Rings respectively, or placing full-sized replicas of the Wright Flyer and a firetruck to acknowledge the anniversaries of first powered controlled flight and the September 11th attacks respectively.
See also: Hacker (term). At MIT, the terms hack and hacker have many shades of meaning,   though they are closely linked historically and culturally with computer hacking (in its original non-computer-cracker sense), collegiate practical jokes, and even culture jamming. The origin of this usage is unknown, but it seems to have been widespread at MIT by the 1960s, and the hacker ethic has since spread into cyberculture and beyond. Over time, the term has been generalized to describe anybody who possesses great technical proficiency in any particular skill, usually combined with an offbeat sense of humor. The manifestation of hacker culture in the form of spectacular pranks is the most visible aspect of this culture to the world at large, but many hacker subcultures exist at MIT, and elsewhere. This article focuses mostly on prankish aspects; for a fuller description of hacker culture, see "Hacker (term)".
Roof and tunnel hacking, a form of urban exploration, is also related to but not identical to "hacking" as described in this article. Some hacks do involve overcoming barriers to physical access (e.g. placing a half-scale Apollo Lunar Module atop the Great Dome), but many other stunts do not require such specialized skills.
Viewed from an anthropological perspective, hacking is a cultural tradition affirming group solidarity, but some hacks can also be viewed as individualistic creative or artistic expression. For example the "Massachusetts Toolpike" hack was a clear instance of installation art  or environmental art. Hacks which involve staged public actions   (e.g. a Zombie march or the Time Traveler Convention of 2005) are clearly a form of performance art, often combined with body art and cosplay. Still other hacks have a strong conceptual art flavor, often satirizing other purported works of conceptual art.   Sometimes the boundaries have been deliberately blurred, for example when a satirical work of "conceptual art" (No Knife: a study in mixed media earth tones, number three) was surreptitiously added to a "serious" art gallery show at the List Visual Arts Center. 
"Tribute", "memorial", or "commemorative" hacks note the arrival, passing, or anniversary of some noteworthy person, tradition, institution, or idea (e.g. the 10th anniversary of Wikipedia). Another broad category of hacks contains strong elements of social commentary or street protest (e.g. "Nth Annual SpontaneousTuition Riot") about events on campus or in the world at large. But the strongest element of many hacks is the sheer joy of conceptualizing something new, and then reifying it with effective engineering, both technical and social (e.g. installing a full-sized mockup solar-powered subway car on the parapet wall around the base of the Great Dome, and then driving it back and forth under remote wireless control from Killian Court, some five stories below, after sundown). 
Like most art exhibitions, the great majority of hacks are temporary installations; most are removed within a day or so by MIT Physical Plant, the MIT Confined Space Rescue Team (CSRT), or occasionally by the hackers themselves. It is a traditional courtesy to leave a note or even engineering drawings behind, as an aid to safe de-installation of a hack. Sometimes, the hacks have been de-installed so quickly that members of the MIT community and the general public have had little opportunity to view them. On very rare occasions, community protests have caused the MIT administration to quietly allow a hack to be re-installed and left for a proper viewing interval. The results of certain hacks (often wall murals ) have been considered "permanent improvements" to the campus environment, and have been left in place indefinitely, most notably the "Smoot marks" on the Harvard Bridge. The MIT Museum maintains an extensive collection of original hacker artifacts and documentation, and displays some larger items semi-permanently in the Stata Center.
Although many traditional college pranks have involved maximizing embarrassment or inconvenience for a victim or target, such antics are usually disparaged by MIT hackers as "unimaginative" or "boring". Often the target of a hack is an abstract concept (e.g. bureaucracy or "political correctness", or entropy), and the prank may or may not be aimed at any specific individual. Even when an individual is targeted (e.g. the "disappearing office"  of newly arrived MIT President Charles Vest), the jest is good-natured, often eliciting admiration rather than anger from the "victim".
Writers for the third-party, independent Internet prankster site Zug once compared humorous responses at MIT and Harvard, by posting similar banners over main entrances to their respective campuses which proclaimed "Institute of Nowlege". Regarding Harvard, they concluded, "The question: is the sense of humor still alive in modern-day Harvard students? The answer, it turns out, is no." Regarding MIT, they said, "So it's official: MIT students have a better sense of humor, hands down, than Harvard students. MIT students are more imaginative, more fun-loving, and probably smarter as well. Truly, MIT is the Institute of NOWLEGE." The Zug pranksters also noted and documented great differences in the reactions of campus police, maintenance workers, and passersby, upon seeing the ironically punned banners.
MIT hacks can push the limits of technical skill, and sometimes fail in spite of meticulous planning. Even these engineering failures have been acknowledged to have educational value, and sometimes a follow-up attempt succeeds. One hack on the Great Dome is documented as having finally succeeded on the fourth try, after a complete re-engineering of both the installed artifact and the installation method.
Smaller projects that can be completed by an individual student are sometimes accorded the honorific "a great hack" by other students, if they combine technical elegance with a hackish sense of humor. For example, an MIT undergrad transformed an ordinary grocery shopping cart into a high-performance electric vehicle, and has been frequently seen riding around campus in his "LOLrioKart". The shopping cart has a claimed top speed over 45 mph, and also has a complex steering wheel linkage and a low turning radius for maneuverability in tight spaces. The student is a strong advocate of the Open Source Hardware philosophy, and incorporates detailed documentation of his projects and a tutorial on building custom wheel hub motors in his blog. The ersatz vehicle has been prominently displayed at many MIT events, as well as the Cambridge Science Festival. As a crowning mark of recognition by the outside world, the LOLrioKart driver once received a traffic ticket from the Cambridge Police, a copy of which is now proudly displayed online.
Some of the best large-scale hacks (e.g. the Caltech cannon heist) have involved multiple teams of hackers working on coordinated but diverse subtasks such as fund-raising, "social engineering", rigging, transportation logistics, gold electroplating, and precision numerical controlled machining, calling on a wide range of technical and management skills. Not surprisingly, some hacker teams have gone on to found start-up business ventures, though they may be reluctant to reveal their earlier exploits until many years have passed.
Though hacks are fairly common throughout the year, a few have become classics whose inside stories are oral tradition, retold to generation after generation of freshmen and pre-frosh.
One classic hack involved a police car with its flashing warning lights operating. The unusual aspect of this hack was its position — on top of MIT's Great Dome. The car was found to be a gutted, junked, heavy Chevrolet, painted meticulously to match the MIT Campus Police patrol cars. The car's number was pi. Its license plate read "IHTFP", the abbreviation for MIT's unofficial slogan. A dummy dressed as a campus patrolman was seated inside with mug of coffee and a box of donuts. Some years later, the police car has now been semi-permanently re-installed in the Stata Center as an all-time classic.
Due to MIT's proximity to Harvard, many hacks involve the annual Harvard-Yale football game. Because of the Cambridge rivalry between MIT and Harvard, hackers often are found at the games, and they have come up with some of the most famous hacks in the Institute's history. 
One such notable hack attempt targeting the 1948 Harvard-Yale football game involved the use of primer cord. One night shortly before the game MIT students snuck into the Harvard stadium and buried primer cord just under the field. The plan was to burn the letters MIT into the middle of the field during the game. However, their work was uncovered by groundskeepers and disabled. During the game the hackers were apprehended while wearing heavy coats on a fair-weather day. The coats were lined with batteries, obviously intended to be used to detonate the primer cord. An apocryphal story is that an MIT dean came to their defense, opening his own battery-lined coat and claiming that "all Tech men carry batteries"; an MIT dean did show up, but he was not wearing batteries. This phrase has since become common among MIT students.
The Harvard-Yale football game was again the target of MIT hacks in 1982 when a weather balloon painted with "MIT" all around was inflated, seemingly from nowhere, in the middle of the field. The next day the Boston Herald ran the headline "MIT 1—Harvard-Yale 0: Tech Pranksters Steal the Show." In 1990 an MIT banner was successfully launched from an end zone using a model rocket engine shortly before Yale attempted a field goal kick. In 1996, the Harvard logos on the scoreboard were hacked from VE-RI-TAS to read HU-GE-EGO instead.
Another traditional hacking target has been the bronze statue of John Harvard, the namesake of Harvard University. The statue itself was sculpted by Daniel Chester French, a famous artist who studied at MIT, who is best known for his statue of Abraham Lincoln at the Lincoln Memorial in Washington DC. Because of its visible location in Harvard Yard and its symbolic significance, the John Harvard statue has been fitted with an unending sequence of "accessories". MIT hackers are hardly alone; Dartmouth College pranksters like to paint the statue green, Yale pranksters prefer blue, and others have dressed the statue in women's underwear. MIT hackers like to go a few steps further, fitting the statue with a plaster leg cast after a crushing football defeat, and disguising the statue as the Unabomber after that infamous Harvard alumnus was arrested. John Harvard has worn a Brass Rat from time to time, and has sported a Halo combat helmet and has donned a Halo assault rifle to mark the release of the Halo 3 first-person shooter computer game. In accordance with hacker ethics, great care is taken to insure that the hacks can be removed without causing permanent damage to Harvard's treasured symbol.
The cleverness of many MIT hacks has even resulted in urban legends about supposed hacks that may not have occurred. One rumored hack involved a certain student's adherence to classical conditioning behavior response, as studied by Harvard Professor B. F. Skinner. Throughout the off-season, this supposed student visited the Harvard football stadium during his lunch break. He dressed in a black and white striped shirt and trousers, filled his pockets with bird-seed, then went on the field, blew a whistle, and spread his birdseed on the field. The result of all of this effort, the story goes, is that on opening day as the Harvard football team took the field to face their opponent, the referee blew his whistle to signal the start of the game, and the field was suddenly inundated by a flock of birds looking for their lunch. Despite sounding like a classic MIT hack, this particular prank has never been verified. The author of a 1990 book about pranks pulled by MIT students stated that he had not come across clear documentation of this tale during his years of research.
On the other hand, at least one hack involved a staged event that never occurred, when hackers convinced major news media that they had created an indoor snowstorm in Baker House dormitory.
When MIT replaced older mercury-vapor lamps with high-efficiency LED lamps to illuminate the Great Dome, hackers started changing the color of the lights to reflect various occasions — Earth Day, the Fourth of July, etc.   Although reprogramming the lights is technically straightforward, these Great Dome lighting hacks are very visible from Boston's Back Bay across the Charles River.
IHTFP is an abbreviation which makes up part of the folklore at the Massachusetts Institute of Technology. It originally stood for "I Hate This Fucking Place" but, due to use of profanity, is often euphemized with other backronyms. Some of the more popular meanings include "I Have The Fucking Power" (Hacking), "I Help Tutor Freshman Physics", "It's Hard To Fondle Penguins", "I'm Hankering To Find Paradise", and "Interesting Hacks To Fascinate People", as well as "I Have Truly Found Paradise", "Institute for Hacks TomFoolery and Pranks" and "Institute Has The Finest Professors." MIT leadership has even adapted the acronym, using it to encourage vaccination during the 2009–2010 flu season with a banner in the MIT medical building that read "I Hate This Flu Pandemic". The precise time of origin is unknown, though the term IHTFP was already widely used at MIT by 1960.
The letters "IHTFP" have been featured prominently on some hacks,     but are more usually subtly embedded within other hacks as an inside joke. A very common motif in the MIT Brass Rat (class ring) is the inclusion of the letters "IHTFP" hidden somewhere within the frame of the bezel.
MIT and Caltech have been occasional prank rivals since Spring 2005, when a group of Caltech students traveled to Cambridge to pull a string of pranks during the prospective new students program at MIT, called "Campus Preview Weekend" (CPW). The stunts included covering up the word "Massachusetts" in the "Massachusetts Institute of Technology" engraving on the main building façade with a banner, so that it read "That Other Institute of Technology". A group of MIT hackers quickly responded by altering the banner so that the inscription read "The Only Institute of Technology".
MIT students retaliated for CPW in April 2006, when students posing as the "Howe & Ser Moving Co." stole the 130 year old, 1.7 ton Fleming House Cannon and moved it to their campus in Cambridge, Massachusetts, thus reprising a similar prank performed by Harvey Mudd College in 1986. To add a technical flourish, a 24K gold-plated precisely upscaled machined replica of the famed Brass Rat (MIT's graduation ring) was tightly fitted over the barrel of the cannon, which was carefully aimed in the direction of Caltech. Twenty-three members of Caltech Fleming House traveled to MIT to reclaim their cannon on April 10, 2006. They were greeted by a larger group of MIT students, who offered them a BBQ farewell party. In exchange, the Caltech students offered a small toy cannon, saying that this was "more MIT's size."
During MIT's CPW in 2007, Caltech distributed a complete fake edition of The Tech (MIT's student newspaper) with the headline article reading "MIT Invents the Interweb". Another article announced the discovery, "Infinite Corridor Not Actually Infinite", referring to MIT's iconic main thoroughfare. The edition included a mock weather forecast, referring often to how sunny Pasadena (where Caltech is located) is compared to Boston, as well as other satirical articles.
In 2008, Caltech students provided a "Puzzle Zero" in the MIT Mystery Hunt which when solved, told solvers to "CALL 1-626-848-3780 ASAP." When MIT students dialed the number, they heard, "Thank you for calling the Caltech Admissions Office. If you are another MIT student wishing to transfer to Caltech, please download our transfer application form from www.caltech.edu. If you are an MIT student not wishing to transfer to Caltech, we wish you the best of luck, and hope you find happiness someday.... "
Around Thanksgiving weekend in 2009, yet another fake edition of The Tech was released, alleging that MIT had been sold to Caltech and would become "Caltech East: School of Humanities". Students would be required to take a core of literature, history, philosophy, and economics, but science subjects would be eliminated. This prank seemed to be a copy of an earlier 1998 hack done by MIT students, which claimed that MIT had been sold to the Walt Disney Company.
In the past few years, MIT hackers have tended to ignore Caltech "nuisance" pranks, instead preferring to perform more imaginatively engineered hacks on their own home campus. In particular, the majority of documented hacks occurring during CPW have been perpetrated by MIT students themselves.  MIT hackers have only rarely interfered with Caltech traditions, rituals, or celebrations. But some MIT hackers do occasionally engage in low-level "sniping" back and forth with Caltech pranksters. For example, hackers made a website http://www.mitrejects.com redirect to Caltech's homepage. Caltech then did the same, with http://www.caltechrejects.com redirecting to the MIT homepage.
A possible change in attitude was inaugurated when a TARDIS, which hackers had placed on the MIT Little Dome (August 25, 2010) and the MIT Great Dome (August 30, 2010), was transported to the roof of Baxter Hall at Caltech (January 4, 2011) by Caltech pranksters, where it remained for several weeks. The traveling time machine subsequently reappeared atop Birge Hall at the University of California, Berkeley (January 29, 2011), and then rematerialized on the Durand Aeronautical and Astronautical Engineering Building at Stanford University (March 18, 2011). The TARDIS came complete with a helpful note explaining how to disassemble it, and suggesting that it be passed on to other unexplored destinations. It remains to be seen whether this new development in "cooperative hacking inter-campus" continues.
The MIT IHTFP Hack Gallery website has an extensive but far from complete catalog of past hacks related to MIT, including numerous documentary photos. More-complete coverage, especially of older hacks, is in the books listed under Further Reading, but these printed volumes are published intermittently. The listing here only summarizes a few salient examples from MIT's long tradition of hacking.