How do you think these phone scammers got their victim's information?

A friend of mine is a 92 year old grandfather of four. Two months ago he got a long distance phonecall from one of his grandsons, Peter ( not his real name ) from Mexico. He said he was arrested for drug possession. That it was a mistake and he was scared of calling his Dad so he called his grandpa instead. Peter gave the phone to a US consulate security staff who told this 92 year old, now troubled grandpa that to get Peter out from the precinct, he needs to send $2,700.00.

My friend, who is wheelchair bound, asked a neighbor to bring the cash to Western Union. After two failed attempts, Western Union said it was a scam. The money never went through. Indeed it was a scam. Peter was with his parents in Hawaii.

For the next few days, these scammers kept calling, giving one new name after another to send the money to. My friend played with them for a while, not telling them he knew it was a scam. He called the FBI to report. The FBI referred him to another federal agency which handles these kinds of scams apparently.

Eventually, my friend decided to just forget what happened since he did not lose his money. This week though, after two months, his granddaughter, Melanie phoned him saying she’s in Berlin and in a hospital after a minor car accident. Not true. Melanie is in New York teaching in a university.

The question that is baffling my friend is how do these scammers get all these info about him? Is it as simple as scammers trolling for information on Facebook for example? He doesn’t know if his grandkids are friends on FB or some other website or whether they are even talking about him.

How do you think these scammers get their info to make the pivotal connections that may fool somebody into thinking a loved one is in trouble and send money to help…the scammers?