Charlotte, North Carolina (CNN) -- James Ian Tyson acknowledges that he is a political activist. He admits he has been arrested a couple of times for relatively minor offenses. But he insists he's not a terrorist.
Tyson, who describes himself on his Facebook page as a carpenter with a "veggie farm," says he has no idea how he wound up on the government's terrorist watch list. He just wants to save the rain forest. The only dings on his record, at least as far as he knows, consist of fishing for trout out of season and driving while impaired.
The 27-year-old, known as "Jimmy" around Charlotte's activist community, was pulled over Sunday near a building where protesters plan their demonstrations. He was charged with driving with a revoked license. And then he was thrown in jail under exceptionally high bail -- $10,000.
The arresting officer asked a magistrate to keep him behind bars for the duration of the Democratic National Convention, which ends Thursday night. He advised against releasing Tyson on his promise to show up for court.
"Why do you feel suspect is a risk?" a bail sheet asked, and the officer wrote: "Known activist + protester who is currently on a terrorist watch list. Request he be held due to DNC being a National Special Security Event." (Both political conventions received the designation from the federal Department of Homeland Security. It freed up federal funding for security and put the Secret Service in charge.)
About 800 protesters marched through uptown Charlotte on Sunday in the first and largest of a week of demonstrations. Only a handful of people have been arrested at the convention in Charlotte, and the Republican National Convention last week in Tampa, Florida -- a sharp contrast to previous years, when hundreds of protesters were arrested.
But there have been complaints at both conventions that the police presence is excessive, and the high security has chilled free speech. Tyson's arrest has some observers wondering whether police crossed the line to suppress dissent.
"The question is whether or not the stop and the arrest and the attempt to get an unreasonably high bond amount was really a pretext for a police officer's selective motivation to censor an individual's political activity," said Jason Huber, a professor at Charlotte School of Law. "If that's the case, then you're in First Amendment territory."
He added it will be difficult to prove what was on the officer's mind when he made what appears to be a legitimate car stop.
"It's a question of what evidence is there to determine intent," Huber said. "There rarely is a smoking gun when it comes to establishing someone's unlawful intent in a particular action. And you have to rely on circumstantial evidence. The circumstantial in this case is a bit suspicious."
Charlotte-Mecklenburg police did not respond to CNN's requests for comment. R. Andrew Murray, the Mecklenburg County district attorney, said that while the high bail was "not typical for a revoked license charge," the court document "heightens our concern for public safety."
Tyson spent Sunday night and most of Monday in jail. He called a legal hot line for protesters and was given an attorney, Derek Fletcher. The Charlotte lawyer got before a judge, Lisa Bell, on Monday and convinced her to lower Tyson's bail to $2,500. He walked free on Monday night.
"I have done nothing wrong and have nothing to hide," Tyson said as he left the Mecklenburg County Jail. "I believe this is an attempt to stifle my First Amendment rights and keep my voice from being heard."
He said he was no longer interested in protesting during the convention, believing police had targeted him. "At this point," he said, "I would like to go home and visit my parents and play with my dog."
Tyson is a volunteer with the Rainforest Action Network and has spoken at Occupy Charlotte events, according to the group's website and Twitter feeds. His attorney said he was jailed in an attempt to muzzle him and prevent him from organizing protests.
"I firmly believe that Mr. Tyson has been profiled and has been singled out as an organizer, and I believe that the government in this case had the intention of suppressing speech before it was even exercised," Fletcher said. "I think it's censorship pure and simple, and I have never seen a $10,000 cash bond on any kind of traffic charge."
Tyson agrees. "I personally believe that this was purely politically motivated," he said, "solely, solely based on the pretext of getting me off the street, pushing me into a cell and throwing away the key for as long as they possibly could."
He owns up to his mistakes, and his brushes with the law.
"I haven't been arrested for anything else even remotely political," he said. "The first arrest was for fishing out of season two days. I messed up, I wasn't looking at the rules right, I apologized. I'm a dedicated catch and release fisherman. I love fishing and fish is one of my passions. My other arrest was for a DWI, which I really regret. But I took responsibility for my actions. As a matter of fact, I was two weeks away from finishing my drug and alcohol courses in order to get my license back."
But he doesn't understand how that got him on the government's terrorist watch list. Federal authorities do not discuss how the list is compiled, or even confirm who is on it, according to the Department of Homeland Security.
"Just being on this list alone is really frightening for me," Tyson said. "This could potentially affect the rest of my life. And they have no cause, they have no cause to do that at all. Some of the questions that tumble around my head are: 'Who's making these lists? Like where's the accountability? Why am I on this list? Why are other people on this list?'
"And most importantly, probably, 'How do I get off this list?' "
CNN's Joe Johns contributed to this report.