Google already does that:
https://www.google.com/transparencyreport/safebrowsing/ https://www.stopbadware.org/blacklisted-by-google
https://www.google.com/transparencyreport/safebrowsing/ https://www.stopbadware.org/blacklisted-by-google
Cloudflare, like Google, does have a similar program and does remove websites that are directly hosting malware or phishing pages. They just don't remove the gray-area stuff, like hacking forums and black market customer portals.