[selmnoo]

I wouldn't say he's a quack -- that implies incompetency. Dr. Oz is actually one of the best heart surgeons in the country, it's rather just that he sold himself for money.

[GalacticDomin8r]

When the majority of your professional advice turns out to be either unsupported or contradicted by evidence, then the term "quack" is warranted.

[DrewRWx]

Or if you overprescribe mercury to treat syphilis infection.