McLean 🌝 is a user on octodon.social. You can follow them or interact with them if you have an account anywhere in the fediverse.
If you don't, you can sign up here.
Regarding squatting usernames I personally would be fine with federations being like "if there's a username dispute we'll defer to the person who owns the corresponding keybase.io account" (or something along those lines; exceptions in cases of super plausible username dupes like "joe")
