WITH the state, EVERYONE is GUARANTEED to get robbed by people with more power than them. If you want to reduce robbery, start by helping people escape the insane notion that "legal" robbery is okay. After that, normal people will have plenty of incentive to organize to defend against private thugs and thieves.
To be blunt, that one individual who saw himself capable of subjugating everyone else wouldn't, because the moment he tried, there would be several million people (including me) ready to put a bullet through him.
RE: The "Social Contract" Excuse