I feel the need to preface this by saying I'm not advocating for this, I'm predicting it will happen. This is not an endorsement of violence, it's a suspicion that violence will occur due to the circumstances that are part of the conversation.

There, now that the disclaimer is out of the way, what you're describing sounds like a recipe for vigilantism. Someone is going to get the bright idea to be Batman and come in with some friends to beat the crap out of the thieves... and this cannot end well.