a former vice president at bank of america idallas, he implemented computer programs to maximize bank revenue. how sophisticated are the programs to get as muc revenue as they can from overdrafts? >> the last one i work on, the cost of the project was in the hundreds of millions of dollars. and represented over a million hours of just programming alone. >> so the banks know what they're doing? >> they do know what they're doing, they're very sophisticated at it. and they have the resources and the man power to get it done. >> the bank of america said it had no comment on drew's allegations. texas real estate agent jory walker discovered one of the new computer tactics that many banks now use. it is called transaction sorting. i means banks can -- it mines banks can clearharges any in der they choose. >> i thought they were taking advantage of the situation. >> a single $100 overdraft led to multiple fees because he said a bank computer program cleared an $850 check ahead of smaller charges that had occurred earlier. >> so they took things out of sequence? >> yes. yeah. and when i ques