"Credible" doesn't have to come with significant hard evidence, I just have to believe it's likely true. e.g. it's not someone making a fake accusation to game this market or because they think prediction markets are unethical and want to damage their reputation.

Doesn't have to be clinically-diagnosed addiction, just has to be someone losing large amounts of money on Manifold to the point where it's making their life worse, but they kept doing it anyway due to some irrational compulsion.

See also:

/IsaacKing/will-at-least-20-users-have-ragequi

/IsaacKing/will-manifold-ban-or-restrict-whale