MMM posts under the handle "MMM."
Unless one was willing to sign up for all combinations of everything Mr. MM, Mr. Money Mustache, Mr.MoneyMustache, etc. etc. there will be some name that one can sign up with that is similar or the same as an MMM moniker.
Hope that makes sense.
Please don't post as MMM so we don't have to delete this account and any other accounts associated with this IP address. :)
Cheers, and locking post.