Not sure if it's still in effect (probably is) but the fighters all had to sign over their likenesses for lifetime when the UFC started going heavy into games back in the PS3/360 days. Jon Fitch got in some hot water with Dana for actually standing up for his rights, was briefly released as Dana said something gross like, "We're looking for guys to work with us, not against us." aka "We're looking for guys who are dumb enough to sign this and screw themselves out of money."
I'm always for the fighters but it's kind of hard to get behind them when they whine about pay and then do shit like sign their likeness away for life and do nothing to better their working conditions *cough*unionize you dumb shits*cough*.