

'C,' GoldenDavid, and AnotherDavid
In one of the FNAF AR trailers, a user named C keeps spamming "I WILL FIND YOU" as a text message.
Some people seem to think that 'C' is a virus, but I don't really see why. It seems just as plausible to me that they're a hacker.
C is associated with Golden Freddy because in the FNAF AR trailer, C is on the television right before "IT'S ME" appears on the walls. So someone is trying to find another person, and is associated with Golden Freddy.
Most people think this is a half baked plot line that never went anywhere. FNAF AR was stopped abruptly before it could finish whatever story it was trying to tell. And we also know that Scott Cawthon didn't start telling his collaborators his story until after Security Breach, so even if the C plotline was supposed to pay off in some way, that doesn't mean Illuminix knew where the story was going.
But what if it's not a dropped plot line? What if 'C' is still out there, trying to find whomever they were looking for?
Before ScottGames.com was closed down, one of the last teasers on the website was found in the source code of the site. A conversation between Glitchtrap and Vanny where Vanny tells him she has "found one."
So what if Vanny has been searching for David Murray the whole time? She initially tries to find him through the FNAF AR system, which uses new and reconditioned Fazbear animatronics. And then when that doesn't work, she sets out to turn Gregory into David Murray using evil Fazbear computer technology.