Update 1:15 p.m. EST Nov. 27: Bank of America, the bank that owns the ATM machine, says those customers who got the unexpected $100 bills can keep the cash, KTRK reported.

The company told KTRK, "This was an incident at a single ATM in Houston caused when a vendor incorrectly loaded $100 bills in place of $10 bills. We have resolved the matter. Customers will be able to keep the additional money."

If Bank of America had required those who got the extra money return it, but didn't, they could have faced theft charges, KPRC reported.

"There's no free lunch. If you receive money that you know is not yours, and you refuse to give it back upon demand, you can, at the discretion of the district attorney, be charged with theft," Sgt. Joshua Norwick told KPRC.

Original report:  Imagine going for $20 from the ATM, but instead, the machine spits out $100. It would seem like you've hit the jackpot, but it was all a mistake for bankers in Houston.

Sunday night, a man went to withdraw money from his account, but instead of getting the expected $20, he got $100 and he did what many people would do, posted it to social media, KPRC reported.

Once word got out, the line at the ATM started as people tried to get free money, KTRK reported.

Fights and arguments broke out until law enforcement officials arrived to guard the machine until the bank could shut down the malfunctioning machine, KPRC reported.

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There's no word how much extra money was taken, KHOU reported.