A Question about a law.

what sorts of numbers?

I don't think this is breaking any law, but perhaps facebook tos. :/ People sell phone information all the time, I imagine for free is even more legal if anything. I'm no lawyer though.

... why are you posting the phone number here too? Trying to help her spread it around?

Spam or just phishing to get numbers to sell for spam etc.

It is possible that they own a large number of phone numbers, so it may not be illegal, if it is, it would be difficult to track, prove, and respond to such action. Best advice I can give is ignore and report it if you can, I don't have a Facebook, so I don't know.

I can say that I keep getting spam from "Adriana", saying that she's seen me on Facebook, we used to know each other, and saying that she had a huge crush on me. It goes on to be flirty, and into trying to get me to log on some kinky webcam thing, which who knows where the link really leads. I think it is funny at any rate.

none.
phone numbers are publicly available, most come in a book.