It is pretty good advice to never "piss off a gangster," but that's exactly what Chad Mendes did recently.

The "gangster" in question is former MMA fighter Chael Sonnen. And well, Sonnen was feeling like Mendes had been avoiding his calls and he really didn't like that. So, in a pretty childish (and not very 'gangster') move, Sonnen went ahead and publicly posted Mendes' cell phone number on Facebook.

For those of you unfamiliar with Chael Sonnen: He is a former MMA fighter who failed three drug tests during his career - which lead to him being suspended from MMA for two years and fired from UFC and Fox Sports (where he was an analyst). Currently Chael has a podcast and works as an MMA correspondent for ESPN.