Anatomically challenged men in large trucks, Critical Mass beat down

Not long after Fil and T3's unprovoked attack, I got a taste of random a$$hole-ness on Friday. Heading out for some climbing repeats, I was cruising along Minnehaha Parkway. I was staying to the right, cars were passing by just fine, when someone honked at me from behind for no reason. I wasn't even on the section that the bike trail runs along. Unfortunately that happens, as all cyclists know. I did nothing, although I was tempted briefly to flip him off. But then as the vehicle passed (of course it was a large pickup truck), the truck veered into me, attempting to run me off the road! This was in full view of all the other traffic along the road. As the truck got closer, I rapped on the side of the truck with my knuckles. This sounds really loud to drivers and is a very effective way of pissing people off, from past experience. But it's also a very effective way of getting anyone who values their large pickups to back off. Just at this time traffic was slowing for a stop sign, so I was able to squeeze past the pickup on up a long line of cars, and never saw (or heard) the pickup again. It was fortunate that there were plenty of witnesses along the road and things didn't escalate. However faced with being run off the road, there's no way I'm going to just take it, and I think I handled it pretty well. I mean, I was seriously considering taking out the multi tool and redecorating the side of this pickup! Now I read that about the same time, cylists and bystanders were getting run into by an unmarked police car, maced and beat down by the police at Critical Mass, unprovoked from what I can tell. WTF?