I end up behind a slow Mazda MR2 as I come up to a left turn lane. He had almost passed the entrance to the left-turn lane with no indication of turning (no signal, no veering towards the lane) so I started to enter the lane behind him. All of a sudden he zips over in front of me and slams on his brakes a good 4-5 car lengths ahead of the vehicles stopped at the light. His car was about where the two red lines are when I started to go around him into the turn lane.

Because the guy was an asshole, I kinda threw my arms up in a "what the hell are you doing?" fashion. I can seem him fumbling around in his car but not sure what's going on. Then he roles down his window and, I think, motions me to go around him. I put my hands up again because I still had no idea what this asshole wanted. He motioned me again, so I started to go around him. He zipped back in front of me and flipped me off. At this point the turn arrow was green and cars were going so he sped off through the light as the turn arrow went away and oncoming traffic started to go. As he sped off I laid on my horn, flipped him off, called him an asshole, and thought that was that. Just some jackass being a jackass.
I get up up to the light and am able to make it through before the main light turns red. As I get up the street I see this asshole pulled off along the side of the road. Waiting for me. As I pass, sure enough, he starts following me. I get on 71N and move over to the 2nd from the far left lane. The guy comes up behind me and gets in the far left lane and drives beside me. I am behind a car so I can't speed up to get around him. There is no one ahead of him and he's driving along at 55 to block me in. At this point I make eye contact with him and very clearly enunciate "YOU ARE A FUCKING PSYCHOPATH. WHAT THE FUCK ARE YOU DOING?" A little bit up the road another lane feeds into the highway on the left. I slow down, get behind him, get over into the new far left lane and try to speed around him. No, this dickhead jumps into my lane to block me, almost hits me, almost runs me off the road. I am fuming at this point, the motherfucker won't let me pass him, won't leave me alone. Finally he starts to pull away and as I get towards my usual exit I start to work my way to the right lane. He was clearly watching me in the rearview the whole time as he starts changing lanes with me. He gets in front of me and gets off at the same exit. He turns right at the red light. I turn right at the red light and he has, once again, pulled off to the side of the road to wait for me so he could follow me again. I was going to the Dunkin Donuts which is on the left, just off that exit, so I cross traffic and pull into the lot. At that point he drives off and I have no idea where he goes.
At that point I absolutely wanted him to follow me in to the parking lot. Though, I'm glad he didn't because I'm not sure what I would have ended up doing. I have his license plate number but not sure what I can do with it, other than keep my out eye for him.
Ever have anything like this happen to you?