Smoking marijuana (Naz)
Selling Crack cocaine (Tyrell Biggs)
Running workmen over (Chris Eubank)
Murdering their girlfriends (Carlos Monzon)
Overeating (Ricky Hatton)
Smuggling Drugs (Chuck Wepner)
Raping women (Mike Tyson)

etc etc etc

Bored fighters seem to get in a lot of trouble between fights - Cus D'Amato kept Tyson fighting every 2 weeks when he was starting out, just to keep him out of trouble!!