You guys can adblock images if you have the extension for Firefox, which you should.
The moderatorship doesn't really have the ability to install extensions, so, you'd need to email the admin if you were really worried about it.
I adblock most signature images, because most people that use this forum have absolutely NO technical aptitude with Photoshop, so, invariably, their sig pics are terrible. The ones that aren't homemade just aren't funny, and that leaves the very small percentage that I can still see.