It seems to me that a very popular form of performance art has emerged as flash mobs.
Flash Mobs are groups of people who assemble suddenly in a public place to perform an act for a brief period of time, then disperse. Usually, the purposes of these mobs are for entertainment, satire, and artistic expression, from mobs doing dances, freeze mobs, pillow fights, etc.
The first flash mob ever was created in Manhattan in 2003, at Macy’s department store, with more than 130 people gathered around an expensive rug.
I’ve contemplated how managing a flash mob is actually possible, but really, it is not that difficult. With social media, it is an effective tool to connect with many many people for a single cause. Think of the amount of participation you could get with adding all your facebook friends in this kind of event. Usually what is included in these invites is the specific task wanted to be achieved and the meeting place and time.