Anarchitecture

"Space Hijackers are Anarchitects who oppose the hierarchy that is imposed upon us by architects, planners and the owners of space.
Our work attempts to confuse the existing language of architecture, not to replace it."

This essay is a good introduction to the Space Hijackers, a group of anarchitects who's projects run from midnight cricket to the infamous Circle Line Party:

"The point of the event was to completely disrupt the way in which the train works in terms of codes of conduct."

..."As soon as  we hit the station everyone was silent... People were asked to bring quick change outfits, so that they   could transform from business like commuters into party animals and back again   at a moments notice. As soon as we entered a tunnel, the band would start up,   the DJ slip on a tune and the party people dance like no tommorrow. As soon   as we hit a station everything stopped and we all tried our best to look like   bored commuters."

I'm all for it, with an important qualification - the distinction between public/private space. Most of the Space Hijackers rhetoric is anti-capitalistic, lambasting the usual suspects (Nike, Starbucks, McDonalds etc). However their greatest successes stem from the manipulation of public space, and their desire to transcend passive acceptance. The seizure of other people's property is one thing, but redefining our shared environment is quite a glorious other.