Some stores are using a new tactic to deal with billions in shoplifting losses: along with charging shoplifters criminally, they're also charging them for the cost of the losses, the investigation — and then some.

PriceSmart, part of the Overwaitea food chain, is among several Canadian retailers demanding shoplifters pay for security expenses. (CBC)

Eleni Prontzos, 17, found that out the hard way after getting nabbed for stealing $20 worth of makeup from PriceSmart Foods in Vancouver. She thought she was off the hook when police weren't called.

"They told me specifically they're not going to call the cops, they're not going to press charges," she recalled store security staff telling her. "We're just going to get your information and you can go."

A few weeks later, her parents received a letter from Overwaitea, the company that owns PriceSmart Foods, demanding $300 for what it called "investigative expenses" incurred by shoplifting.

The letter threatened that Prontzos could be taken to small claims court and that she could also be criminally charged.

Eleni Prontzos and her father Peter Prontzos review a letter sent by PriceSmart demanding $300 to cover the cost of investigative expenses related to the theft of $20 worth of makeup. (CBC)Peter Prontzos, Elani's father, refused to pay.

"If they were serious, they would have the kids charged. All I see it as is a moneymaking operation, by terrorizing parents and making things more difficult for kids. And I think that's disgusting," he said in an interview with CBC's Marketplace.

Several retailers, including the Bay, Zellers, Loblaws and Shopper's Drug Mart, have adopted the tactic as a means of recovering the millions lost to shoplifting, Marketplace discovered.

The demand letters ask for up to $700, but none of the retailers would say how many people actually pay up.

Brian Lawrie, who operates Aclaim Civil Loss Recovery Systems in Toronto, defends the process, saying his company helps retailers recoup money from shoplifters.

"It's a huge problem, and the retailers have found that this particular process — it's a fair process, it's a reasonable process, and it is intended to be a deterrent process," he explained.

Legal aid lawyer Martha MacKinnon says retailers can legally ask for money from people caught shoplifting, but without a court order people are not obligated to pay. (CBC)

Toronto legal aid lawyer Martha MacKinnon, who has seen hundreds of the demand letters, said it's legal for the companies to ask for the money, but she tells parents they don't have to pay.

"The heart of the issue — is there an order by a lawful court that says you must pay, and there isn't. So our advice is you don't have to pay anything until there is."

MacKinnon considers the tactic bullying and intimidation.

Regardless of whether she'll have to pay, Elani Prontzos says she's learned her lesson: that one stupid and impulsive act was far more trouble than it was worth.