Fraud issues have been sweeping through multiple US online gambling sites in the past few weeks, raising questions about whether or not the security around account information is sufficient.

DraftKings acknowledged the issue on Twitter yesterday, posting the following statement to its news account:

“DraftKings is aware that some customers are experiencing irregular activity with their accounts. We currently believe that the login information of these customers was compromised on other sites and then used to access their DraftKings accounts, where they used the same login information,” the statement read in part. DraftKings’ Paul Liberman also ensured full restitution for the customers affected by around $300,000 of fraudulent transactions.