Often times, religious people will characterise non-believers as "angry atheists". I find this expression ridiculous; it's a hollow ad hominem that gets thrown out there to dismiss any argument from the atheist by attacking his character.
First of all, being angry does not mean you're wrong. Sure, people who are angry are often angry for bad reasons, or act unreasonably because they are angry. That does not mean that being angry automatically means you're irrational. there are situations where anger is absolutely justified, like when your freedom is being suppressed for idiotic reasons.
Atheists have every right to be angry at theists when they are trying to legistlate their religion through the government. Freedom of Religion means freedom FROM religion, so governments should not endorse any religious position.
Secondly, the claim that atheists are angry or militant is a classic case of projection on the part of the theists. The theist is projecting his own frustration at people "rejecting" his god, onto those people, and assuming they must be angry at his god.
Sorry, Atheists don't believe in god so we're not angry at him, we're frustrated by the things YOU do in his name. The worst thing that atheists actually do is start debates and law suits.
PS: I didn't intend to make prof. Dawkins look quite so goofy, this was a bit of a rush job D:
Single layer stencil, spraypaint.