http://wowbreak.com/content/RemoveWoWForumAds

The link above has a clear method for removing Blizzard ads thanks to the firefox community.

My problem with Blizzard doing this is the fact that they are trying to earn money by people who are seeking support to play a game that they have purchased. A great many people visit Blizzard forums due to game breaking bugs, or system errors when playing the game, etc. These people should not be subject to further attempts at financial extraction from Blizzard. It is appalling and disrespectful.