Never heard of them? Well golly gosh where have you been?
Here is some vintage Yes Men to get you up to speed:
On November 29, 2004, an email comes in to DowEthics.com [ a mock site set-up by the Yes Men] BBC World Television wants a Dow representative to discuss the company's position on the 1984 Bhopal tragedy on this, its 20th anniversary.
So they politely respond to the email and set a 'Representative' taking full responsibility for the Bhopal disaster:
This is where you can find out more http://www.theyesmen.org/