You misunderstand - not divulging what triggered the suspicion isn't lying. Claiming a phone number is required due to suspicious activity, when in fact it is required of almost all new accounts, is.
Another covert spam fighting way is when one of the platforms require you to set up a phone number "for two factor authentication", basically not letting you to use their service unless you actually provide the number. There are multiple platforms framing the issue in this way.
Facebook once required that you set up 2 factor authentication and they promised that the phone number won't be used for anything else. Few years later, they started spamming users at those phone numbers with notifications about what their friends did. And since this year, those numbers can be used to search for users on the platform.
The big issue with giving those platforms your data is that you hand over control. Even if they promise you something.
> And since this year, those numbers can be used to search for users on the platform.
And someone really should go after them for it. Last month an abuser from a decade ago found me on facebook and messaged me out of nowhere. Upside is i was able to tell him off, but I know many other people would have a far more.. trying encounters.
Creating an account from a system which no Twitter tracking pixel has ever seen may well be suspicious, where suspicious means statistically correlated with accounts create to spam or acts as hostile bots.
