There is an expectation in the web hosting industry that when a bad site (child porn, phishing, etc) pops up on your network, you take it down. CloudFlare effectively shields who is hosting the site so that you can't pressure them into taking it down. An entire cottage industry of bulletproof hosting companies has popped up that actively advertise CloudFlare protection.
I used to work on an extremely large free DNS provider. Even though the service was free, we were still obligated (morally and by our upstreams) to take down malicious sites.
There is an expectation in the web hosting industry that when a bad site (child porn, phishing, etc) pops up on your network, you take it down. CloudFlare effectively shields who is hosting the site so that you can't pressure them into taking it down. An entire cottage industry of bulletproof hosting companies has popped up that actively advertise CloudFlare protection.
I used to work on an extremely large free DNS provider. Even though the service was free, we were still obligated (morally and by our upstreams) to take down malicious sites.