A little over a month ago, Facebook announced they were buying the maker of the Oculus Rift headset for upwards of $2 billion. Now suddenly another company claims its their technology that make the virtual reality device worth buying. ZeniMax Media has sent multiple letters to Oculus and Facebook, claiming employee John Carmack improperly took ZeniMaxs intellectual property with him to Oculus. Carmack was a former id Software (owned by ZeniMax) employee.