Are gas stations holding consumers' money hostage? They're not supposed to do this unless they tell you, but as the 10News I-Team reports this sneaky practice is happening at gas stations all over the county.Paul Lewis tells the I-Team he's not happy about the charges made to his checking account."It's abusive in my opinion," he said, explaining how he used his Visa debit card to buy $20 worth of gas at an Oceanside Chevron station"I made an ordinary gas purchase," he said.When Lewis checked his bank records on-line he found something out of the ordinary."Lo and behold I found my $20 debit for the Chevron station in Oceanside and a $50 debit for the Chevron station in Oceanside," said Lewis.Lewis purchased $20 of gas, but his bank account showed another $50 tacked on. The total amount of his cash tied up is $70 and Lewis wants an explanation."I called my bank and said there must be a mistake, I've got an extra charge on my account," said Lewis.But Temecula Valley Bank tells him there is no mistake. The charge is called a pre-authorization hold."The operations officer said that's just the hold they put on the transaction when you make the purchase," said Lewis.As soon as you swipe your card at the gas pump, the extra money is charged to your credit or debit card. In some cases, the extra money is released when you finish pumping the gas. In other cases, the additional money is held. It depends on the gas station and the consumer's bank.Another consumer, Kathy, tells the 10News I-Team about a pre-authorization hold she said received at an ARCO station on Sports Arena Boulevard. She said her card had a $100 hold, lasting two days on her account.Kathy said, "I was unable to purchase $33 in groceries because of this."Customers say the pre-authorization hold isn't what steams them. It's the fact that nobody told them about it."It takes my money without my permission, they use it for three days and then choose whenever they get around to it to give me it back," said Lewis.Merchants don't need your permission to request a hold, but they do need to warn you about it.As the 10News I-Team found out, the California Attorney General has issued an opinion on this matter saying:"When a customer uses a debit card to purchase gasoline, service station owners may not cause a hold to be placed on the customer's bank account " without informing the customer. This applies to holds that linger after you drive away and total more than the amount of gas you purchase.The 10News I-Team checked the Chevron and ARCO stations involved finding the stations have no warning signs.The consumer warning: if you pump, be prepared. Paul Lewis said he's thankful he monitors his accounts closely."That extra 50 bucks could have over drafted that account."To avoid the pre-authorization holds, consumers should pay inside the station.Starting this fall, Visa begins something called "Real Time Clearing" which means gas stations will clear transactions within hours, if not minutes. Consumer groups are encouraging all gas stations to adopt this new process.Both ARCO and Chevron say they're not to blame for the extra charges, telling the 10News I-Team it's the customer's banks that set the holds.Consumers with complaints about pre-authorization holds should contact the California Attorney General's Public Inquiry Unit.