Banking sites and anybody who suffers from any sort of attack, whether it's scraping, DDoS, bots, bruteforcing...
Does everybody get those attacks? Probably not, however, Cloudflare centralizes the attacks into a single IP reputation database so, if at some point, a certain node was abused on x site that uses Cloudflare, anybody who is routed through that node will have a poor experience browsing CF sites.
This approach of centralizing IP reputations has its own flaws and benefits, Tor Nodes aren't inherently given a bad reputation, it just happens that if 90 people are using the tool for all the good things, 2 assholes can abuse the IPs and have them blacklisted on almost any website, whether it's Cloudflare, Imperva, Akamai, PX, you name it. Cloudflare is the most known name but there are tons of other E2E/B2B providers that don't show up as often.
Does everybody get those attacks? Probably not, however, Cloudflare centralizes the attacks into a single IP reputation database so, if at some point, a certain node was abused on x site that uses Cloudflare, anybody who is routed through that node will have a poor experience browsing CF sites.
This approach of centralizing IP reputations has its own flaws and benefits, Tor Nodes aren't inherently given a bad reputation, it just happens that if 90 people are using the tool for all the good things, 2 assholes can abuse the IPs and have them blacklisted on almost any website, whether it's Cloudflare, Imperva, Akamai, PX, you name it. Cloudflare is the most known name but there are tons of other E2E/B2B providers that don't show up as often.