WTF?! It's been seven years since HP first became embroiled in controversy for pushing out a firmware update to its printers that disabled third-party ink cartridges. Since then, it has faced lawsuits and countless complaints about its cartridge DRM, which it claims is about protecting quality for the customer, and definitely not a way of forcing people into buying its own expensive products. Yet despite all the outrage, HP is still pushing out these updates.

HP's Dynamic security feature works by having the printers check inserted cartridges' security chips or electronic circuitry to confirm they are from HP. "The printers use the dynamic security measures to block cartridges using non-HP chips or modified or non-HP electronic circuitry," explains HP, which adds that the feature is "to protect the quality of our customer experience, maintain the integrity of our printing systems, and protect our intellectual property." Nothing about money, then.

The backlash from the Dynamic security's introduction in 2016 led to HP apologizing and initially removing the DRM. However, it reappeared in 2017.

New, official ink cartridges are expensive, so introducing a feature that prevents HP printer owners from buying discounted third-party ink isn't going earn the company a lot of goodwill. HP has already paid out millions in settlement fees after class-action lawsuits were brought by consumer groups and users accusing the firm of "underhanded" tactics and anti-competitive behavior. The most recent of these was a $1.35 million payout to customers in four European countries.

But HP hasn't abandoned its cartridge DRM plans, as Reddit users (via Ars Technica) are discovering. "HP have updated their printers to outright ban 'non-HP' ink! They no longer shows the 'can't guarantee quality' message, but instead cancels your print completely until you inset a HP ink cartridge," wrote Redditor grhhull. "After contacting HP, they advised 'this is due to the recent 'update' of all printers.'"

It's unclear which printers have received the updates and when they were pushed out. The OfficeJet 774, 6978 and 6968, and the OfficeJet Pro 6970 are some of those named on HP's support page.

What's even more jarring for users is that the updates could, without any notice, brick third-party cartridges that they had been using in their HP printers.

Ars notes that HP has been careful to admit no wrongdoing even when paying out its class-action settlements. Instead, the company has focused on making it more clear which of its printers have the Dynamic security function. That's certainly not going to appease people who've just found their printer is no longer working.