The Yes Men, a culture-jamming activist duo, and the anti–tax dodging group US Uncut were the players behind a widely circulated (and false) AP report stating GE would be returning its entire 2010 tax refund of $3.2 billion to the US Treasury.

The groups told ABC News they are forced to impersonate public figures and companies in order to break into a media space that is oversaturated with the loudest voices and those with the best public relations departments.

“Corporations spend billions of dollars a year shoving lies down that pipeline, so we have to impersonate them just to get information out,” Yes Men spokesman Michael Bonanno told ABC News. “Our lies are designed to be recognized as lies almost instantly. But we have to impersonate these companies that already have a voice to say something, otherwise nobody would listen.”

US Uncut followed up the publishing of the AP story by posting a press released titled, “US Uncut Welcomes GE’s Change of Heart,” complete with a fabricated interview with US Uncut spokesman Carl Gibson.

And while the prank might have disappointed activists eager to see a corporation that paid no federal income taxes while raking in $14 billion in worldwide profits last year finally pay its fair share, the false report did have a dramatic effect on GE’s stocks. The “tiny guerilla team” managed to knock $3.5 billion off GE’s market value in a matter of hours. “Obviously, GE can’t possibly be expected to do the right thing voluntarily; their stock would keep plunging,” says Gibson. “That’s why we must change the law.”

This certainly isn’t the first time the media has been hoodwinked by the Yes Men. The group has performed other “identity correction” stunts such as Andy Bichlbaum’s legendary appearance as “Jude Finisterra,” a Dow Chemical spokesman, during a 2004 BBC World appearance in which he announced that Dow planned to liquidate Union Carbide, the company responsible for the chemical disaster in Bhopal, and use the resulting $12 billion to pay for medical care and clean up.

And again in 2009, the group staged a news conference to falsely announce that the US Chamber of Commerce had reversed its stance on climate change legislation.

The idea behind the Yes Men’s activism, of course, isn’t to raise the hopes of victims only to crush their spirits in the last hour. The real purpose is to force companies like GE to defend their wildly unethical behavior, which GE ultimately did today. Deirdre Latour, a GE spokeswoman, said, “It’s a hoax and GE did not receive a refund,” a statement that conflicts with reports GE did indeed claim a tax benefit of $3.2 billion.

The lesson here is that if it sounds too good to be true, it’s probably the work of the Yes Men.