Gym teacher accepting bribes

I swear I'm not making this one up either. It seems a gym teacher at a middle school was accepting a dollar a day bribes from students so they would not have to take gym class. While I give the teacher credit for turning himself in on this one, I have to think why you'd risk even such a lousy job as teaching (I can only assume it's lousy even though it pays more than any job I've ever held) for such a relatively small payout.