Online Poker service SealsWithClubs which is claimed to be the world's largest bitcoin poker site has admitted their database server containing user credentials compromised by the hackers.
They said the stolen passwords are hashed and salted but urged users to change their password. If you used the same password anywhere else, you are recommended to change there also as precaution.
Ars Technica pointed out a link to the InsidePro forum's post in which an user with online moniker "StacyM" has asked other users to crack 42,000 hashed passwords.
StacyM is offering $20 in Bitcoins for every 1000 unique cracked passwords. Thousands of passwords have already been cracked. He didn't mention the source of those hashes. However, some cracked passwords such as "sealswithclubs", "pokerseals" is appeared to be from the SealsWithClubs website.
SealsWithClubs promises to improve the security measures in the near future including 'ability to permanently lock withdrawal address', 'lock accounts account access except for certain IP addresses'