This guy took the high road - once he had the license plate and an address, this could have taken a very different turn. If you're into someone for $4,000, it's a coin flip whether they invest effort into getting it back, or invest another $4,000 for someone else to get you back. If you are going to steal from someone, always keep that in the back of your mind... you don't know what type of person you're stealing from. Maybe it's an easy mark, or maybe it's a vindictive psychopath that would love an excuse to pull your teeth out in his basement over the next 30 days. "Risk vs Reward" and all that...
Until something similar happens to them, people often take for granted living in a society where the legal process is relatively accessible to those needing it.
