Six Flags announced yesterday that their tickets will have new fine print on the back, barring entry to convicted sex offenders. Their spokesperson says Six Flags added the new wording as “an extra level of protection.”

Against what? With all those kids in the park everyday, it sounds like a good idea, but it’s completely untenable and unrealistic.

My engineer, Kevin, used to work at Six Flags, and tells me that the park holds about 40,000 people (5,000 in Hurricane Harbor, the rest on the rides side). How are they possibly going to check them all? There’s no way they can do background checks on every person who passes through the turnstiles — they have enough trouble keeping the backpack-checking line moving on a busy day.

Six Flags acknowledges this impossibility, but says that someone acting inappropriately could be subjected to a check and thrown out of the park. Isn’t that the way it should be already, regardless of your criminal history? The rule is simple: if you misbehave, you gotta go.

This may stem from an incident in 2000, when a 19-year-old employee molested three girls while strapping them into a ride. He was arrested, there was a lawsuit, and Six Flags settled for over a million bucks. But he wasn’t a visitor. He worked there. In that case, doing background checks on all of its employees might have tipped them off to a problem — if he had a record, of course.

Like so much of what passes for protection in America these days, this move may make people feel more secure, but will not make actually make Six Flags any safer.