What you're looking for is called a paywall or ad-blocker detection script. For Invision Community (IPS) forums, you'll want an IPS-specific plugin from the Invision Community Marketplace (or third-party vendors like Invisionize) or a custom JavaScript snippet that detects missing ads by checking elements/script execution, which you'd integrate into your forum's themes/hooks, often using solutions from the IAB Tech Lab, AdSanity, or Advanced Ads for inspiration, as these solutions work by looking for blocked ad requests or zero-height ad containers I'll bet one of the third party guys has something already but they take a lot of updating because adblock browser plugins continually change to thwart ad-blocker detection scripts. forum.invisionize.pl - Support Invision Community (IPS4, Invsion Community 5,IP.Board)[IPS Marketplace] Enhanced AdBlock BlockerWith this plugin you will be able to detect AdBlock browser plugin that blocks your website ads. It will display a block message that will disable all website if the user didn't disable his AdBlocker.The above as a starting point but you'll obviously want something updated and current. You'll just have to start contacting people and looking around. I know SOSinvision has a lot of stuff and so do a lot of the other third party guys which I hope will chime in since I don't know them all. Good luck.