The Kindle Fire is clearly designed for one thing: to make it easy for customers to buy Amazon’s goods.

But some are starting to question whether that convenience comes at the cost of security. In a Thursday column, technology reviewer Mark W. Smith identified the one-click feature on the Kindle Fire as a “big security problem.” The feature, which allows customers to store their credit cards with Amazon and avoid having to reenter their information each time, doesn’t have enough protections in place to avoid unauthorized purchases, Smith said.

It’s a problem similar to the one Apple faced when it came to light that parents around the country were facing high credit card bills after their kids made in-app purchases. Parents would authorize their credit cards once, and their kids would make micro-purchases that added up to big bills because Apple had a long window before it required repeat authorization. The company has since changed its policy to require a password for all in-app purchases.

The potential for bill shock is even worse on the Kindle Fire, because the Amazon shopping app isn’t limited to smaller purchases aimed at helping you get to the next level of a game. Since users can buy anything from Amazon through the shopping app, the costs could be much higher.

Users can reduce the risk of unauthorized one-click purchases by putting a passcode on their devices and locking the screen each time they set the device down.

Amazon has said that it will release an update to the Kindle Fire, which will make improvements to address some security and privacy concerns, such as making it possible to edit the activity history that shows up on the device’s main screen.

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