The Electronic Frontier Foundation is criticizing HP for using a security update to also install a function that when recognizing a non-HP printer cartridge triggers a printer to shut down.

A letter posted on its site expresses alarm "that the printers now automatically verify whether its ink cartridges are official HP ink and not competitors' products or even refilled HP cartridges." If these printers detect a competitor's cartridge, printing ceases.

The EFF asserted this tricks customers by tying a security patch to the installation of the technical countermeasure to exclude third-party cartridges and works against customer interests by giving them a reason to mistrust updates while putting them at risk of future infections that could affect their networks.

HP knew of the "bait-and-switch" for at least six months before activating the "anti-feature," so customers buying HP printers assumed they would be able to use printer cartridges from other manufacturers, the EFF asserted.