Last week, Visa, Mastercard, and American Express adopted a new code to categorize sales at gun shops, allowing them to monitor and track sales of guns, ammunition, and gun accessories.

Gun control advocates claim the card companies can use this to “flag potential threats,” but in reality, it is ripe for abuse.

Among the concerns, this type of surveilance could create a backdoor gun registry, further enacting gun control through a public-private partnership.

Furthermore, it creates a system that is ripe for data leaks full of sensitive gun owner data.

Read more at NPR.