As for hating someone that we don't know, I think that the word "hate" has been diluted so much that it loses a lot of its poignant meaning. For example, I don't mean hate to be as visceral as you are picking up on Dipre, which in your defense, you're going by the literal definition of the word "hate" whereas I'm going by the diluted version of hate that seems to be permeating everyday usage. So, as I had said sometime when the original fight was starting, perhaps "strongly dislike" would be a more accurate term.
My point is, that there are very few things in life that I hate. Similarly, most of my objects of hate are very temporary. In addition, I think that you're allowed to hate people you don't know, as long as you acknowledge that there's a possibility that the "real person" isn't the same as the media representation. Therefore, I think that everyone has the right to hate the media representation of Lebron, or Favre, or Roethlisberger, or the guys from Jersey Shore etc, however, saying that you hate Jersey Shore is a lot easier than saying all of that.
In addition, I think it's a bit hypocritical to say that nobody can hate someone they don't know, when people constantly hate other sports teams, and other posters here. For the longest time I hated a700 and Gom, but I never technically knew them (and I don't hate either of them now). So I don't think that one can say, or even act like they don't hate someone they don't know. I mean I don't know the CEO of Bank of America or Comcast, but I'd love to cage fight them both right now.