Yes, I do. All you have to do is look up the IP of someone connecting, and if its not a home IP (e.g. a datacenter IP, like inside an IP range that a larger hosting company owns), its most likely a VPN or something similar.
Instead of writing this comment you could've taken one of the nodes you run (since you seem to be so qualified) and simply install openvpn on it and connect to it. Then go and visit sites that would be restrictive, or visit any site that tells you more about your IP.
But sure, go off and question my qualifications because you haven't considered this, or tried it, or ran into the issue yourself.
Plus, the way Discord, for example, does phone numbers, is that they just block anything they arent quite sure about.
