Not to sound like a paranoid conspiracy nut, but...
It is strictly speculation, but could philanthropist Glen Davis have been murdered because of his support of the conservation movement? He gave millions a year to the World Wildlife Fund and the Sierra Club and that may not have sat well with some of the more extreme "traitorous liberals should all die" types out there. He survived a vicious beating two years ago that was never explained and his attackers were never caught.
I'm not saying he was killed because of his involvement with the environmental movement - I don't know enough about the other aspects of his life to say that there wasn't some other motive for the murder. But when I see the kind of overblown rhetoric that gets thrown around on the right side of the blogosphere about how this person or that person should die in some horrible way because they don't have the same beliefs as the poster, I always wonder how long it's going to be before some nut job take the idea to heart. Certainly, this has happened in the abortion debate. Call those doctors providing abortions baby-killers enough times and viola, some fetus fetishist dingbat decides to be judge, jury and executioner and plant a "pro-life" bomb at a clinic or shoot a physician in front of his family.
I don't know whether Davis was assassinated for giving millions to the World Wildlife Fund and the Sierra Club, but sadly it isn't beyond the realm of possibility

Speaking of nutjobs with bombs - While I'm sure sensible people everywhere would feel bad if there had been violence at Jerry Falwell's funeral, apparently it was his own guys that were ready to start throwing firebombs. Wasn't Fred Phelps and his addled band of cultists supposed to be picketing there?