I mean the 'things' that appear on web pages, the prompts to sign up for newsletters, accept cookies, create accounts, install apps. They are difficult to block

I mean the 'things' that appear on web pages, the prompts to sign up for newsletters, accept cookies, create accounts, install apps. They are difficult to block because they're part of the document (rather than a new pop up window) and can be implemented a million and one ways.