Can't edit anymore, but this was not exactly an invitation to email me names and phone numbers to text. I don't know the legal implications of sending mass unsolicited messages to people whose phone number I obtained through downloading questionable data.

If you really want to warn people and you have a plausible explanation for the legal basis on which we're doing this, then I would definitely be able to contribute resources to your cause.

But also, frankly, they put this info there and configured it to be public themselves. Doesn't mean they don't need to be warned about this misconfiguration, but it's quite different from if there had been a data leak caused by facebook that facebook isn't telling the users about. I don't feel the need to drop what I'm doing and spend a couple days looking into the legal status, coming up with a good narrative / what to text them, gathering other people, figuring out how a regular human being can send hundreds of text messages without doing custom app development (if avoidable), dealing with the aftermath...

TL;DR: if you cleared the list of todos in the previous sentence, then my resources you shall have.