[distances]

Not just for this purpose, but Facebook accounts in general. If you try to create one without a valid number and/or seemingly valid friends list, chances are it's blocked in no time.

I don't know a thing about Google Voice, but I for one wouldn't bother setting up some fake numbers to create a fake account to use my own hardware.

[shortandsweet]

That's fair as long as FB specifies these requirements ahead of time. I'd be unhappy if FB didn't tell you and this is only discovered after the fact.