Originally Posted by M3ta7h3ad
http://www.bbc.co.uk/crime/law/powersofarrest.shtml (Scroll to bottom)
In the uk the general public have the right to place people under a citizens arrest, providing they have witnessed them commit a criminal act.
Myself, I arrested 3 blokes after being assaulted by them. Then got the police involved whilst I held them on the floor, as opposed to transporting them myself to the station.
Its a certain possibility for you to encounter (not sure on laws in the USA but would have thought the capacity should be there) and if I had someone such as yourself damaging my car you can expect to be confronted with "reasonable force" and brought to justice over your actions.
You'd need to be pretty well versed in the law to get away with that here. Holding the "blokes" is false imprisonment under most circumstances and state laws. You get to defend yourself and others up to the point when there is a clear escape from harm, beyond that the criminals have more rights than you do.
Case in point, a former instructor of mine took out some home invaders and held them in his garage until police arrived. Charged with false imprisonment. He was within his rights to defend himself and his family, had they been there, even with lethal force since they had weapons. He did not have the right to detain them.