The entire incident happened within a span of two minutes, according to Carla Villeta, a student at Mount Royal University.

A group of males entered the Apple Store at Chinook Centre wearing sunglasses and hooded sweatshirts. They approached the iPhones on display.

"Next thing I know, they were grabbing them off the tables and the alarms rang," Villeta said in a message to CBC.

Villeta said one male snatched the display iPhone from her hand as she was viewing it, nearly grabbing her own iPhone, which was on the table.

The culprits quickly fled the scene, at which point Villeta began filming.

Thieves wearing sunglasses and hooded sweatshirts made off with dozens of iPhones from the Chinook Apple Store Saturday night. Read more: <a href="https://t.co/hUnntSlbnN">https://t.co/hUnntSlbnN</a><br><br>Video courtesy Carla Villeta <a href="https://t.co/Z1166ps4Ws">pic.twitter.com/Z1166ps4Ws</a> —@CBCCalgary

The thieves made off with dozens of iPhones, according to Calgary police, and were caught on video surveillance.

Sites like Kijiji and eBay are popular destinations for those looking to buy devices at reduced prices, but consumers should be careful to ensure their purchases are secure. (CBC)

Tracking numbers

Each smartphone comes equipped with an International Mobile Equipment Identity (IMEI) number, a unique serial number that allows stolen phones to be identified.

The dozens of iPhones snatched from the Chinook Apple Store will be identifiable using these numbers.

"There's no two phones in the world that have the same one," said Calgary digital security expert Tom Keenan. "When you want to get service from a carrier, say Bell or Rogers, they'll ask for the IMEI number. That is the key that you register your phone with."

Stolen phones are reported to a database, Keenan said.

"[If they're reported stolen], you're going to have some trouble registering that phone," he said. "So people who are looking to buy phones really want to make sure that it's registered."

If you are looking at purchasing a smartphone on a platform such as Kijiji or eBay, it's important to check the IMEI number beforehand.

"If you've bought stolen property, you've bought stolen property," Keenan said. "So my gut feel says maybe you should have checked a lot harder before you did that. I guess it's possible that you could go back to your credit card company and try to somehow deny the transaction.

"But if you met a guy in a parking lot somewhere and handed them two thousand and he handed you a phone, that's probably game over."

Buying used devices online

Kent Sikstrom with Kijiji Canada said buyers should request IMEI numbers from sellers, no matter whether or not it feels awkward to do so, and keep an eye out for various red flags.

"The most obvious red flag is the pricing. We see this with virtually any item on a second-hand platform," Sikstrom said. "If you're looking at a brand new phone, like the iPhone X, [and you notice] the phone is suspiciously below market price … you have to ask yourself the question, 'Is this too good to be true?'"

Sikstrom said Kijiji relies on a number of filters and artificial intelligence to determine whether or not an item is potentially legitimate or illegitimate.

"Our AI allows us to really assess a user's online behaviour and posting patterns to make determinations as to whether or not they might be legitimate," he said. "But for the most part, it is difficult to assess either from a human standpoint or a machine standpoint.

"Which is why we also work extremely closely with the police when it comes to assisting them with criminal investigations."