There are two different things here, and I'm not sure I understand all the issues.
1. The personal vendetta. I understand this. (At least, probably)
2. The posting -- without permission -- of a sex tape made without Hogan's knowledge and in a private location. This seems morally indefensible to me. This is where I get a bit lost as to people defending Gawker. Shouldn't posting such a video be illegal?