People keep thinking / saying it's an actual virus. It isn't. It's closer to spirit inhabitation/possession by an electronic entity - which phrasing I use specifically, since it appears that while many or most of them are types of AI, they could theoretically also be E-Ghosts. It also requires a very particular set of circumstances and implants - by which I mean the entities that make up the Sybil "virus" generally have a reason to go after a particular individual or set of individuals, and require a certain amount of built-in technological assistance to succeed.
Which means that in part the event is going to happen to specific individuals, remain relatively rare, and require very unique and special timing. It also means that electronic entities cannot themselves 'come down with' or 'get' or 'acquire' or 'fall victim to' the Sybil "virus". They might, however, be members of the Sybil community ...