Have you ever come up with a random theory with no proof and you're just kinda like "Screw it"?
So here it is:
In FNAF, someone's out to get revenge on you. Idk why, maybe you stole their candy when they were kids or peed in their Cheerios MOVING ON. They're now a master hacker, so they've programmed the animatronics to try and kill you. But to the people who work for Fazbear Entertainment, the code and everything looks like nothing but a glitch.
Totally random