The U.S. Chamber of Commerce was royally punked earlier this month, falling victim to an elaborate ruse by a group of political activists. The business group is peeved, calling the prank "commercial identity theft masquerading as social activism." Now it has filed suit.

That's an odd place for an aggressive proponent of tort reform — and ferocious opponent of "lawsuit abuse" — to find itself. Consider the facts:

A group called the "Yes Men" is the object of the Chamber's ire. The Yes Men, which recently released a movie, is a self-described ensemble of actors "best known for posing as corporate executives in order to reveal how corporate greed negatively influences public policy."

In l'affaire de Chamber, it developed a dummy Web page that mirrored the Chamber's online presence. It announced the startling news that the Chamber had made a dramatic "about face on climate policy" and now favored "a stiff carbon tax and correspondingly strong incentives for industries."

The climax of the hoax was a staged news conference at the National Press Club. A member of the Yes Men troupe, posing as a U.S. Chamber of Commerce spokesman named "Hingo Sembra," fielded reporters' questions, achieving with perfect pitch the grim gentility that characterizes Chamber communications. Before long, an agitated Chamber employee came on the scene, confronted the Yes Men and informed the puzzled assembly that they had been had.

A video recording of the proceedings, in all their wince-inducing detail, has been posted on YouTube, where it's been viewed more than 200,000 times and received a boatload of media attention.

The Chamber announced Monday that it had filed suit against the gonzo Yes Men gang. It tries to cast the suit as a garden-variety action to protect the organization's intellectual property — specifically, two registered trademarks. The organization's chief in-house lawyer called the suit "a customary response by any organization faced with this type of misconduct by the defendants."

But that's simply not the case. Far from a narrowly cast trademark protection lawsuit, this is blunderbuss, seven-count complaint filed by a major Washington, D.C., firm in U.S. District Court, with the Chamber asking for an injunction (including removal of YouTube videos), a jury trial, damages, attorneys' fees and "such other relief as may be appropriate."

The Chamber protests that it is "a strong proponent of free speech and encourages public debate on issues of the day." But the Chamber is trying to stifle free speech and punish political parody with its superior resources and army of high-priced lawyers.

The Chamber counters that "the defendants are not merry pranksters tweaking the establishment. Instead, they deliberately broke the law in order to further commercial interest in their books, movies, and other merchandise."

We'll see. Ultimately, that's what the federal court will decide.

Members of the public, meanwhile, can view the evidence online and render their own judgment. There's already ample proof to support this conclusion: The U.S. Chamber of Commerce's complaints about our litigious society shouldn't be taken seriously.