Check their terms.[1]<p>First of all, you're giving them a license to your content for their purposes. <i>"By submitting, posting, or publishing your content, suggestions, enhancement requests, recommendations, feedback, information, data, or comments (“Content”) to any Website or Online Service, you are granting Cloudflare a perpetual, irrevocable, worldwide, non-exclusive, royalty-free right and license (with the right to sublicense) to use, incorporate, exploit, display, perform, reproduce, distribute, and prepare derivative works of your Content. You will retain ownership of your Content, however, any use of your Content by Cloudflare may be without any compensation paid to you."</i> For example, Cloudflare could make a copy of your site and monetize it.<p>Second, you can be cancelled at any time. <i>"We may at our sole discretion suspend or terminate your access to the Websites and/or Online Services at any time, with or without notice for any reason or no reason at all. We also reserve the right to modify or discontinue the Websites and/or Online Services at any time (including, without limitation, by limiting or discontinuing certain features of the Websites and/or Online Services) without notice to you. We will have no liability whatsoever on account of any change to the Websites and/or Online Services or any suspension or termination of your access to or use of the Websites and/or Online Services."</i> For example, if you were promoting a product that competes with Cloudflare, your site could be taken down with no notice.<p>Those are the big ones. Also, there's no uptime guarantee, an overreaching indemnification clause, and the usual "I am altering the deal. Pray I do not alter it further" clause.<p>It's about as bad as the Apple App Store.<p>[1] <a href="https://www.cloudflare.com/website-terms/" rel="nofollow">https://www.cloudflare.com/website-terms/</a>