Buying a used iPhone or iPad? This neat trick can help make sure it's not stolen from Apple.

A Reddit user has revealed a tip you can use to check if a "used" iPhone or iPad was stolen from Apple using its IMEI number.

The tip follows a week of protests, and sadly violence and looting across the U.S. in the wake of the killing of George Floyd in Minneapolis. Several Apple Stores in the country including the Minneapolis store have been targeted by looters, who have broken into stores and stolen accessories for sale and display devices used on the shop floor.

Apple's in-store display units are useless beyond the store's walls. They are imaged with special demo software which can be used to track the phones and disable them if they are removed from the store. However, that doesn't mean someone isn't likely to take advantage of looting to try and sell some of them on. So here's how to spot whether a phone or iPad was stolen from Apple.

The tip from Reddit users 3hitbye is very simple. If you run the IMEI number of a device that happens to be an Apple demo unit, there will be two very clear signs that it was stolen.

The first is the purchase date, which the poster notes will be an "impossible purchase date" like 1984, or some other such whack date. The second key indicator is a locked carrier status that reads "Chimaera/Blacklist Device Policy."

You can check this yourself on a couple of websites. The two attached to the post are iUnlocker and SickW. If you're about to purchase a second-hand device from someone, be extra cautious and ask for the IMEI number. If you run it and see either of those two key indicators, then you should stay well away from the device, and you might even want to report it to the authorities.

Finally, please note that these websites are unofficial and even a "negative" result on the above tests does not protect you from other potential issues, so where possible, you should absolutely try to buy used phones from reputable outlets.

You can also read our guide to buying a used iPhone here.