Bloggers at risk from more than governments

Following up on my earlier post on the Committee to Protect Bloggers comes this gem from Reason magazine. (It's from the February issue but I just happened across it; evidently after seeing the cover I wasn't as inclined to read that particular issue.

It seems that a group called Islamic Army has threatened to murder a number of Iranian bloggers because of 'insults to Allah' on their blogs.

I hate to contribute to stereotypes, but does anyone know of any other non-governmental groups who go around threatening bloggers?