Not a lawyer. There's nothing you can do because he got there first. "Formal trademark" means nothing because unless you've trademarked in every class and file

Not a lawyer. There's nothing you can do because he got there first. "Formal trademark" means nothing because unless you've trademarked in every class and filed for it before he registered the domain, there's little you can do. Even if you came before, there's still little you can do without a significant amount of money. Talk to a lawyer if it's that big a deal, though.