The aforementioned 15 U.S.C. § 1129 from the other answer indeed looks somewhat applicable, but I highly doubt that anyone would agree that a random myfirstname individual, one who is not expressly famous or known by any significant proportion of the population
under such name, is somehow intrinsically owned a myfirstname.com
domain name, just because they're the first one to file a lawsuit against the
present owner that's offering it on sale.