Edit: Well, apparently it wasn't 8,000 death threats - just many death threats in 8,000 comments. The correction comes from Blair himself. Shocking, can't trust the media to report things accurately...
Fox News' Facebook page was flooded with threats calling for the rape, crucifixion, and murder of atheists. The cause? Blair Scott, Communications Director of American Atheists, appeared on Fox News to defend their lawsuit against the Ground Zero cross. Just look at some of the examples one blog collected:
Frankly, however you feel about the cross lawsuit* it irrelevant - no one deserves to be treated like this. I can't get over how despicable these messages are. I may disagree strongly - very strongly - with some religious people, but I never wish them dead. I know this doesn't represent all Christians, but it certainly debunks the notion that religion automatically makes you a good person.
*And if you want to know how I feel about it... go read the incredibly well written article by James Croft. No point rehashing what he already said so eloquently.