Cloudflare will respond to a ping, but a request will pass through. Clever folks will realize that finding which AWS region(s) host(s) the ELB is trivial with c

Cloudflare will respond to a ping, but a request will pass through. Clever folks will realize that finding which AWS region(s) host(s) the ELB is trivial with curl --trace-time and ping, since you can deduce the RTT from Cloudflare's proxy through to the ELB. You also know geographical Route 53 and other tricks aren't in use, because you automatically lose that information through Cloudflare. I'm fairly confident it's in us-east-1 based on a quick glance.