I do know that the casinos I work for (none have very robust poker products) never ask for social security cards though if we cannot verify your social security number, we may ask for a W-9 Form to verify it. I cannot vouch for why they are asking for docs. I get the latter, but the former has me scratching my head? Neither of the other two sites requested this. They are now asking for signed Social Security card along w/ utility bill w/ banking info. I have signed up / deposited on Stars & MGM.