Well, whenever you are stolen by someone, if guards spot this you will have a message that you can kill the thief (X has been spotted stealing...).
If I steal from someone when they're unconscious to I get a thief tag on me?
Because of thief-related faggotry I've started to plasmagrenade thieves on sight. The guards may shoot me but I got nothing to lose.
The other thing would be to "cap" the number of successful attempts per day for master thieves by inserting a increasing variable to reduce their % success after the "cap".