Sleepwalker is a pejorative term for those who wear a VR headset in public in obnoxious or dangerous ways. The middle 21st century was rife with people who could see and hear you, but were so hooked on the dopamine rush of always dreaming that they barely cared. Many walked right into vehicle traffic or died other accidental deaths.
The name is derived from the Medium Crown's technology, which induces its user into a hypnagogic state during use.