Not under this Yamataks "personality" at least. Otherwise he'd be presenting some proof.
He was banned on Barter so he had to create some new aliases, like Kağan.
As you can see, his bad rep escalates real quick on every new account, so he's now operating as "Yamataks".
I'm surprised he's still allowed to roam on SteamTrades. I understand it's against the rules to have multiple accounts.