You cant talk crap about the following fighters or their saddo fluffers will get hurt:

Miguel Cotto (Only a stubborn few)
Manny Pacquiao (Anyone with anything that mentions Pac in their screen name)
Antonio Margarito (Very small faction of delusional posters)

Honorable mentions
Ricky Hatton
David Haye
Floyd Mayweather

Other than that you can talk crap about people wives, girlfriends, Moms thats all fair game and no one is ever offended but better be careful talk about crap about those fighters...you've been warned!!