CBS News Correspondent John Blackstone reports one of those posters was enough to bring two Secret Service agents knocking on Brown's door in search, they said, of "anti-American material."
"They flipped out their badges and they said that they were from the Raleigh department of the Secret Service branch and whatnot," said Brown, "And I was, like, Whoa!"
Looking thru the door the agents studied the posters, particularly one criticizing the use of the death penalty in Texas when George Bush was governor.
"The lady, she was like, 'Oh, that's nothing,'" said Brown.
The Secret Service in Raleigh told CBS Newsthey received a tip from "a good citizen" about threatening material in Brown's apartment and that it was their duty to check all possible threats to the president.
The visit left Brown shaken — and offended.
"I mean, it's my apartment. I have the right to post anything up in my apartment that I please."
Srini Kumar, an American of Indian descent, produces irreverent bumper stickers — "Darn The Gov't" — that can turn the back of a car into a political statement.
"Now, here's a good one," said Kumar, pulling out a sticker that said "Fascism Has Many Disguise."
To sell his stickers on the Internet, he chose an attention-getting name: UNAmerican.com. But after Sept. 11, his Web site — and his stickers — got the attention of the FBI.
"When the FBI is investigating bumper sticker companies, we have, in my opinion, a crisis on our hands — a civil liberties crisis," said Kumar. "When we're told that we live in a free country, free shouldn't just mean like 10 percent off!"
Rick Smith, a former FBI agent who is now a security consultant, doesn't see it so severely.
"That's a benign type contact — I mean, the FBI is looking for help. They're looking for the public's assistance."
In the new war on terrorism, Smith says agents are struggling to close a huge gap in intelligence.
"What they're trying to do is develop sources of information to identify suspects — that's what the game is all about."
But it is, of course, a game that is now deadly serious — forcing Americans to re-evaluate what's acceptable in the balance between security and civil liberties.
Eye on America: Watching You
Part 1: Big Brother is Watching, Listening