I can not answer for parked, but I have done my own analytics since the beginning of the year, and its official; some people hate domainers and are on a mission to cause damage and it is very likely that they are members of this forum.....
....Consequence, this guy just got his company website and store terminated.
I don't know if it's domaineers that they are after only. It's easy to feel you're being singled out and attacked. From my experience, I've seen a lot of clients websites get hacked or attempted to be hacked. When they parties are caught, they always have the same mentality of teenager pulling off Halloween pranks. I used to think that they were picking and me and my clients.
Today, I'm just have been prone to believe there's just notion of meanness and mischief that makes people do this. Most hackers and tricksters have a huge egos that are centered on their scripting 'kung fu' abilities and fueled by a belief that they can't get caught. The only thing keeping them from being caught is records keeping from some ISPs and hosting services.