Privacy rights have a hell of a lot more to do with PokerStars getting sued by the criminal/thief than it does with protecting said criminal.
By giving out personal information they could be breaching multiple laws like the Fair Credit Reporting Act & opening themselves up to million dollar lawsuits.
Suppose Will finds this guy with PStars help and kills him or at the least severely cripples him(I know I would want to if it were my money), then that criminals' heirs are going to sue Pstars for millions. Fair, probably not. Legal responsibility, definitely. Ask anyone in the financial/insurance industries to what extent their companies go to to protect personal information. Millions of dollars in settlements and legal fees depend upon this protection of identification. PStars can't just give this degen criminal's personal information out. It sux, I know.