CHICAGO -- Brian Gill stood near the gates of Great America in Gurnee, Ill., on a recent afternoon -- unable to set foot inside.
With the American Eagle roller coaster looming overhead, and joyous screams echoing from behind the wall, Gill clutched the document that explains his exile.
"Attention!" it says. "As a result of your infraction you are not permitted on the property of Six Flags Great America for the remainder of ... your life." A security guard had penciled in the term of his sentence.
Gill said he parked his motorcycle without paying during an outing last year to his family's favorite theme park. Then he made it worse by trying to re-enter after a guard told him to leave.
That landed the 41-year-old dad on the ever-expanding list of people who have been banned from Great America. The length of banishment can be from a day to a lifetime, police reports show.
Some entered dangerous and restricted areas. Others committed theft or brought pot into the park. Two beat up a mascot.
Park officials declined to be interviewed about the banishment policy. They issued a statement that says it's part of an elaborate system that keeps guests safe.
"Out of the millions of visitors our park gets a season, only a very small percentage chooses not to follow the rules where they are no longer welcome to return to the park," Great America said. "We do not tolerate inappropriate behavior."
Security experts say the threat of exile encourages visitors to stay on their best behavior. Formally banning a troublemaker bolsters the park's ability to prosecute repeat offenders, law enforcement officials say.
It's a policy practiced by many places that serve the public. In the Chicago area, everything from shopping malls to casinos have imposed lifetime bans on people whose bad behavior makes their patronage unwelcome.
"The trick is finding a way to make it work," said Lauris Friedenfelds, a Chicago-based security expert.
Gill knows of no way to appeal his sentence, or earn parole. A letter he sent to Six Flags Great America President Hank Salemi was not answered, Gill said.
"I'm never going to get to take my child to Six Flags," lamented Gill, of New Berlin, Wis. "It's so weird. You come to this place since you were a little kid, and they're like, 'You can never come here again. Ever.' "
It's like being banned from summer, Gill said.