Long before Facebook bought Oculus VR for $2 billion — before Oculus even launched its successful Kickstarter campaign — famed video game programmer John Carmack sparked a wave of interest in the virtual reality headset by showing off an early duct-taped prototype at game conventions. Now, it may come back to bite Oculus and Facebook in the ass. Now that John Carmack works for Oculus, his former employer ZeniMax Media claims that it owns part of the intellectual property in the headset, and may sue Facebook and Oculus over those ideas in the near future. The Wall Street Journal obtained two letters from ZeniMax lawyers sent to Oculus and Facebook, which claim that Carmacks contributions were invaluable to the initial success of the Rift: It was only through the concerted efforts of Mr. Carmack, using technology developed over many years at, and owned by, ZeniMax, that [Oculus founder Palmer] Luckey was able to transform his garage-based pipe dream into a working reality, the letter reportedly reads.