Maybe not-really-ISPs should be made ineligible for certain privileges / rights given to real ISPs. Like not-really-doctors can't do everything that real doctors can (grasping for a better analogy).
Other entities could punish them by revoking peering agreements. Or if CloudFlare wanted to play hardball, they could deny access to their CDN from AT&T IP ranges. That would be punishing AT&T customers further, but it would get their attention quickly and they'd complain to their ISP.
