Revercecaptcha.com is a very deceptive site. It may periodically attack Google Chrome, Mozilla Firefox and other browsers. The main purpose of these pop-ups is to infect your browser with the feature of permanent web push notifications. The pop-up says that this is some sort of human verification. However, it is absolutely dangerous for you to click on “Allow”. This way, your browser will be immediately hijacked and infected with a lot of annoying ads.