World’s largest Bitcoin poker website has been compromised and around 42,000 users’ credentials are at risk. Seals With Clubs used SHA1 hash functions to encrypt the passwords, but SHA1 is outdated and easy to crack if not salted. The data center used until November was breached, resulting 42,020 hashed password theft. The site also mentioned that they are working to improve security of the website and would implement additional security measures, including two-factor authentication and login from a limited number of IP addresses.
Source: https://thehackernews.com/2013/12/SealsWithClubs-bitcoin-poker-hacked-password-dump_20.html