I once came out of a supermarket to find some scroat had keyed the full length of my car, (definitely wasn't a trolley). I was absolutely incandescent with rage, and I suspect if I'd caught the culprit in the act I'd have probably lost it completely, so I do get the frustration.
BUT, the problem with vigilantes and acting outside of the proper judicial process is that the wrong people WILL get pasted. People acting on mistaken identity, rumours or malicious lies, or more likely simply stupid people getting carried away in the moment.
And I'm sorry, but anyone pleased with a lynching for an alleged theft resulting in a death, whether indirectly caused or not.....well enough said.