Been there, and it sucks. Your dad's being an idiot.
Also, if he doesn't know anything about computer games, his reaction is quite understandable, most kids do get addicted to games, and violent games get all the bad media. There's a lot of speculation as to what games do/cause, with only a small portion of it having any real truth. Naturally it's the people outside the gaming community that hear these things and get the wrong idea before doing any research.
I don't really want to get into this, but, well, people are stupid. Games get 'all the bad media' in large part as a result of said media feeding on the general population's suspectability to hysteria and willingness to believe that the responsibility for all the worlds problems can be laid at the feet of anything that isn't them, and the media is fully willing to spread those stories because it turns a profit and protects their interests. The only speculating going on is that begun by the ethically bankrupt and perpetuated by the ignorant.
As to the bolded part, no, they don't.