This is why most CDNs like Akamai don't allow illegal sites to use their service. You have a shared-destiny with all their other customers. If someone goes after a site like Rescator for selling credit cards online or blocks 4chan for child-porn, your site can be affected because it's served from the same Cloudflare network.
A few CDN's have build entirely separate networks with a different ASN's for keeping their more questionable content away from the bulk of their customers. I've not checked if Cloudflare have done this or not, but it would make a lot of sense. This segmentation can really help. For example, a bunch of hacker groups use Cloudflare and by putting them all on the same IPs, you can magically stop them from DDOS'ing each other.
A few CDN's have build entirely separate networks with a different ASN's for keeping their more questionable content away from the bulk of their customers. I've not checked if Cloudflare have done this or not, but it would make a lot of sense. This segmentation can really help. For example, a bunch of hacker groups use Cloudflare and by putting them all on the same IPs, you can magically stop them from DDOS'ing each other.