There are very few ways to qualify someone before you mug them, but thieves often prefer to rob women because they're assumed to be easy targets, an assumption that is often proven to be wrong.
MMA fighter Monique Bastos was headed to the gym with a few friends when a stupid thief tried to steal her phone while riding by on a bike. However, Monique wasn't going to give up her phone without a fight, and the would-be thief ended up with nothing but a hard hitting life lesson.
(Caution- video contains violence)
As you can see in the video, the thief she has locked up in the dreaded "triangle" wished he was dead, and his punishment definitely fit his cowardly crime. Curious about what he's yelling as she chokes him out? Read a translation here
-Via Huffington Post
It's rather tame as Brazilian justice goes. You can find dozens of videos on Youtube or Liveleaks of thieves shot dead by armed citizens and off-duty officers.