MrSeb writes "If you’ve been paying any significant attention at all over the last several years, you’ve undoubtedly heard or seen advertisements for businesses that promise to save you money on printer ink cartridges. Specifically, by letting you refill the ink once it runs out, rather than forcing you to buy an entirely new cartridge. HP, understandably, doesn't like this practice — and even goes as far as saying that refilling its printer cartridges doesn't work. After touring its recycling plant in Smyrna, Tennessee, it sounds like Matthew Murray is almost convinced that HP is telling the truth." Link to Original Source
If it happens once, it's a bug. If it happens twice, it's a feature.
If it happens more than twice, it's a design philosophy.