Re: Why don't [they] just ask Facebook?
"infamous Graph API is installed either by the Facebook app or any number of third party apps that use Facebook's API."
On a related matter: I don't use Facebook on my phone, I use it very little (and reluctantly) on desktop Interweb, etc.
My last three mobiles have been Moto G with stock Android ROM, with no obvious pre-installed Facebook. If I know that an optional app is closely linked with Facebook, I don't install it, which is one reason why I have no Whatsapp,
Is there an easy way for people to check whether their phone(s) or other devices are infested by this Facebook Graph API pestilence?
Historic note: in the dim and distant dark days when GUIDs were a novelty and allegedly considered to be "progress", I was surprised to keep seeing 08-00-2B in the GUID in various places (typically in MS Office documents?). And then I found out why it was there, and what it meant, and decided there was going to be trouble ahead one day. Allegedly these things work differently now. Maybe they do.