Do you think that people do this deliberately? I've always thought that people are just blissfully unaware of anything on 2 wheels and I always try to ride with that in mind.
Typically, it's blissful ignorance and inattentiveness. There are the odd times that they are being malicious; it happens more often than you may imagine. I'm speaking about motorcycles, at least.
I've personally had assholes speed up to not let me over, cut me off, the usual. Then I've had the fools who would swerve at you in an effort to spook you or worse. I've also been boxed in on the highway, but I was never in any real danger.
I have heard worse stories, though. I know of a guy from the west, IIRC around the Nevada area, who rides year-round. Sport-tourer. Well, apparently he had a few too many instances of the truckers 'playing' with him at night and running him off the road. He insisted that the only way he stayed safe was by keeping a bigass Ruger .44 Mag revolver open-carried over his jacket on his shoulder. He got the stainless version so it was easier to see at night, when the BS usually happened.