Literally the DataMiner-5000.
Many web sites use Cloudflare to filter access. The problem is, you're paying for a service that regularly goes down or fails, steals visitors data and blocks Tor, useful if it's a forum, but horrible for pretty much everything else, as you there is no reason to block people who want anonimity, and by doing so, people are less likely to trust you.
Any corporation that has massive amounts of unencrypted data has been confronted by the government. Judging Cloudflare's central role on the internet as the centralized hub of infinite internet connections, I think we all know that Cloudflare and feds work together. Cloudflare can see everything that is unencrypted, such as personal information and passwords.[1] It determines user's location via IPs (note that IPs can also give out your ISP), and it acts as a man-in-the-middle, Cloudflare sees what the users does and what they are looking at, and redacts the info so only them know.
First of all, Cloudflare uses non-free JavaScript, second of all, JavaScript IS the WORST THING TO HAPPEN TO THE WEB. and Cloudflare single-handedly made it obligatory on almost all sites. JavaScript can be used to spy on users, log their IP, steal hardware info including OS, screen size, browser and even the user's GPU, without the user even clicking anything. Yet, Cloudflare decided to force everyone to have this security risk on.