Yes, but I selectively block certain websites. For a long while, wired.com and cultofmac.com were getting really annoying (to name 2 that really bugged me). Wired fixed theirs; can't say the same for cultofmac.com
If a website has good intentions, I understand the need for ads and will disable it. I don't mind seeing ads and usually find them interesting, so long as their not annoying.