Having recently upped my visibility of traffic incoming from the internet, I have to agree with the sentiment that Cloudflare are providing a useful, worthwhile service, and the reason that they've grown to the extent described is that they do a very good job at it, and outran their competitors by a wide margin.<p>The internet is a cesspool of malicious traffic.<p>I was wondering why my Lets Encrypt certs weren't auto-updating, and it's because in my recent upgrade to my primary firewall I hadn't setup an incoming port forward for port 80 (because, ironically, everything is served via 443 these days). But Lets Encrypt requires incoming port 80 for its domain ownership verification - or at least the option I'd setup, which was the easiest at the time.<p>I decided to log (to view) the traffic coming in to port 80, and it was a relentless stream. It'll still be a relentless stream now, but it's all bouncing off the external wall rather than an internal one.<p>Same with port 25, and that's gotta be open if you want to receive email. I was actually looking forward to what Cloudflare will do with email protection from their recent acquisition. If I see many repeated attempts at connecting to port 25, I block the full /24 permanently.