we all know dev is mining Ziftr with his gpu miner).
ziftr dev is US registered company myVBO LLC, you've just publicly accused them of fraud. Bad move.
Can you prove they don't have one.

That's irrelevant, this isn't the school playground. When legally challenged, the sockmuppet making the accusation is obliged to provide proof in order to defend themselves against a charge of libel. Be careful how you write it if you can't prove it.
Cheers
Graham