HP should apologize to customers and restore the ability of printers to use third-party ink cartridges, the Electronic Frontier Foundation (EFF) said in a letter to the company's CEO yesterday. From an ArsTechnica report:HP has been sabotaging OfficeJet Pro printers with firmware that prevents use of non-HP ink cartridges and even HP cartridges that have been refilled, forcing customers to buy more expensive ink directly from HP. The self-destruct mechanism informs customers that their ink cartridges are "damaged" and must be replaced. "The software update that prevented the use of third-party ink was reportedly distributed in March, but this anti-feature itself wasn't activated until September," EFF Special Advisor Cory Doctorow wrote in a letter to HP Inc. CEO Dion Weisler. "That means that HP knew, for at least six months, that some of its customers were buying your products because they believed they were compatible with any manufacturer's ink, while you had already planted a countdown timer in their property that would take this feature away. Your customers will have replaced their existing printers, or made purchasing recommendations to friends who trusted them on this basis. They are now left with a less useful printer -- and possibly a stockpile of useless third-party ink cartridges."