I had this happen to me when I lived at the beach in San Diego. Dude parks in my assigned parking spot at my condo, I tell him politely he can't park there because it's our assigned parking. Dude gets verbally abusive towards me. My woman chimes in, he gets verbally abusive towards her. Upstairs neighbor adds her $.02, he starts in on her.

I walk out into the parking lot to ask the guy what's his deal, he starts gesturing like he's gonna come at me. I told him that if he gets into my personal space It's gonna get ugly.

Dude rears up and acts like he's gonna go nose to nose with me, I fear for my safety and push him backwards, hard. He falls flat on his ass and spills his beer (imagine that!).

His tune then changes "YOU CAN'T PUT YOUR HANDS ONE SOMEONE....I'M CALLING THE COPS!!1!" ("1" for added anger effect)

Cops come, tells me that he was indeed in the right and next time that happens I should call them first. In this instance, the guy wants me to go to jail, he's gonna press charges so they start telling him that if he presses charges then they said he'll go to jail too... told him I would place him under citizen's arrest for public intoxication, disorderly conduct, etc. At this point I'm mad and begin saying things like "Are we gonna get the same holding cell? Because I'll finish that motherfucker up in there and eat his ass for dinner"...

So ended up dude didn't press charges because he could see where it was going.

Depending on where you live is gonna have a lot to do with the outcome. I moved to Washington state where there's a "mutual combat clause" stating that if two people wanna rock then they can as long as an officer is present. I'm not an advocate for violence but if someone gets up in my shit, it's not gonna be pretty. You get what you give.