Wondering if someone has experience of this - I recently cancelled my service but the cartridges are almost full. You're supposed to send them back but that seems a waste, they're not going to recover the ink. They're supposed to stop working as well, but my printer is disconnected from the internet, and the cartridges still work...so...anyone have experience of this? Do they really expect the cartridges back? Are they uniqely identifiable (sounds unlikely)?