OKLAHOMA CITY -- More Oklahomans are being affected by what could be the largest security breach ever.
In 2008, someone hacked into the Heartland Processing information compromising the accounts of 40 million Americans.
Thirteen thousand Midfirst custormers were affected by the breach. Now, some Bank of Oklahoma customers are receiving similar letters of a possible security breach of their accounts.
Click here for more information on the security breach and tips on how to keep your accounts.