Some people love ads on web sites, others hate ‘em. The latter group can smile, at least if they use Firefox as their browser. A new add-on forFirefox, called Adblock Plus, deletes all those annoying ads, from banners to Google ads which come from search terms you enter. That might seem likea welcome addition, but it’s certainly not going to make those in the burgeoning online ad business happy. They don’t want users to be confronted by a lot of white space, especially whenthere’s big, big money to be made by search engines and others charging for ads. For now, with just 2.5 million Adblock users on Firefox, it’s not likely to be a major threat (lookaround and you can find an ad-on for Internet Explorer 7 that blocks ads). But as Adblock is adding over a quarter of a million new users a month, that could change. At the moment, then,Adblock largely remains beneath the radar. But in a statement, Microsoft did say, “The range of add-ons available does include ad blockingsoftware. It would not be appropriate for Microsoft to comment on the merits or demerits of a specific add-on, or group of add-ons. Provided they have not been designed with malicious intent and donot compromise a user’s privacy or security, Microsoft is pleased to see new add-ons that add to the range of options that users have for customizing their browsing experience.”