Enraged Boston officials are gearing up for a legal assault against those responsible for a terrorist scare that shut down major roadways and subway lines for parts of Wednesday.

The three suspects, who may be members of Al Qaeda, appear at right. George W. Bush is considering holding them at Guantanamo Bay indefinitely without trial.

Authorities last night were retrieving 38 magnetic signs depicting the cartoon cast of “Aqua Teen Hunger Force” - blinking ads that were placed under bridges, outside Fenway Park, on storefronts and other in locations.

They were installed as part of a Turner Broadcasting System marketing blitz for the show, but for much of the day, police treated the signs, which measure about 12 by 18 inches, and feature protruding wires on one side, as potentially dangerous.

The investigation shifted when they moved one of the signs into a darker area, which prompted the lights forming the character’s image to brighten into color. A brilliant Boston police analyst recognized it as a cartoon character and concluded it was likely a publicity stunt.

“This is a hoax - and it’s not funny,” said Gov. Deval Patrick, apparently under the impression that his landslide victory in November allows him to dictate what is funny and what isn’t.

Rumor has it that Sen. John Kerry initially voted to allow the ad campaign, later voted against it and now condemns it passionately. Sen. Hillary Clinton has commissioned a poll to gauge public opinion before stating her position.

The two men accused of placing the cartoon ads/bombs pleaded not guilty today in a courtroom packed with supporters and a crush of reporters. The Boston Herald wryly observes that they were paid only $300 apiece for the stunt, which will cost taxpayers nearly $1 million.

War of the Worlds, it wasn’t. But did local and state authorities jump the gun? Or should these characters (or the network) face punishment for this stunt after taking a funny idea too far in the post-September 11 world? Is the community just bent out of shape because the terrorist mastermind is flipping them off (see below)?

If anything, the Boston Globe notes, the ad campaign exposed the wide generation gap between jumpy government officials who reacted as if the signs were bombs and 20-somethings raised on hip advertising.

The ads were placed in 10 other cities over the past 2-3 weeks with no adverse consequences. Is Boston old and out of touch?