The author is a bit late to the party - this used to be a thing. IIRC you could just enter the phone in fb search and it would spit out the name + fb link even for private profiles.
Someone I knew scanned down a whole country's numbers in a couple of months (there was some rate limiting and that's about it) - and that guy just did it for fun. I'm sure there were plenty of shady companies doing the same thing.
After a while FB started cracking down on this. They even admitted they knew about it for years. Can't find a link but IIRC that was 4-5 years ago.
Someone I knew scanned down a whole country's numbers in a couple of months (there was some rate limiting and that's about it) - and that guy just did it for fun. I'm sure there were plenty of shady companies doing the same thing.
After a while FB started cracking down on this. They even admitted they knew about it for years. Can't find a link but IIRC that was 4-5 years ago.