The arms race is upon us! See http://www.antiadblocker.com and http://www.antiadbuster.com. These software packages attempt to defeat ad blocking software, through various methods. If a user is found to be running ad blocking software, he is prevented from accessing the web site's content. Given that antiadbuster is free and ad blocking software is becoming more popular among IE users, it seems likely that before long Mozilla users choosing to avoid ads will be restricted from more and more web content. The URL I have listed above is an example of a file download (anything after the / is treated the same) protected by the AntiAdBlocker product. In Mozilla 1.1b on Linux, it keeps me out after determining I'm blocking its popups, using the usual Mozilla prefs. What I'd envision would be that a window.open call for what Mozilla considers an 'unrequested window' would be allowed to run, and that window would be fully built, content for it downloaded, etc. But it would never be drawn to the screen, the user would have no idea it ever existed. Any status bar changes, resizes, and so on targeted at any such window would be processed as normal. This would all (hopefully) ensure that any conceivable checks by anti adblocking software would find the window was successfully displayed to the user, since any images in the window would be downloaded from the server, and so on. After some amount of time (2 seconds or so) the window could be automatically closed by the browser, to avoid unnecessarily wasting resources, just as if the annoyed and exasperated user had closed it by hand. Another nifty feature of this method would be that it isn't available to that huge army of IE users using ad blocking software. IE will display whatever it gets, so if anti adblocking becomes widespread, it'll kill the adblocking software market. Mozilla will stand alone as the only way to browse without ads. Two things could result, both good. One, lots of people will start using Mozilla. Two, a smaller number of people will use Mozilla and get this anti-anti adblocking capability, so the anti ad blocking people won't consider us worth their time to target. Does this sound feasible to do? Perhaps there is a better way to accomplish this goal -- I haven't looked into all the methods the anti adblocking software uses, my suggestion is simply the "brute force" method that IMHO would be most likely to be impossible for the anti adblocking folks to work around. I don't know the Mozilla code at all though, so while this seems pretty easy to me (add a flag to the data structure associated with a window to say "ad blocked, don't display", etc.) it may not be. I wasn't sure what component to file this under, please change as appropriate. I thought about changing Severity to "major", since it will be a major loss of function when this sort of thing becomes widespread, but since it isn't a big problem yet, I left it alone.

slice1900@hotmail.com: thank you for this interesting suggestion. Since it involves high-level considerations within the browser, and not the low-level functionality of JS Engine, let me reassign this to Browser-General for further comment by interested parties. I'm not sure what the final component would be for this -

*** This bug has been marked as a duplicate of 161176 ***