he is masquerading as an expert on the internet This silly novel is masquerading as a serious historical treaty
Examples from VerbNet
They serve a restricted role on the bench. Dina masqueraded as a lawyer. Dina acted like a cretin. He had served in financial planning positions.
Examples from SemCor
Professionally a lawyer, that_is_to_say with dignity, reserve, discipline, with much that is essentially middle-class, he is compelled by an impossible love to exhibit himself dressed_up, disguised-, paradoxically, revealed- as a child, and, worse, as a whore masquerading as a child.