Because that means you might be blocking legitimate stuff too. My company, https://TalkJS.com https://TalkJS.com, makes a pluggable messaging component. Custom

Because that means you might be blocking legitimate stuff too. My company, https://TalkJS.com https://TalkJS.com, makes a pluggable messaging component. Customers embed it in an iframe, created by a 3rd party (from their perspective) hosted js file. Currently, it doesn't rely on cookies for security but we easily might change that. Same for other pluggable content, say Disqus and many more. I would be very sad if an ad blocker would block us because we dare use appropriate tools for security.