Thanks, xyzzy. That is reassuring. I guess I thought FM was invincible, but a scam is a scam! I talked to my Mac lady, and she said to consider this a prank call, that I shouldn't worry about it. You have echoed her advice, so other than beefing up my passwords I think I'm going to do just that. I don't want to deal with a password manager. I do see the benefit of one, but I don't have the brain power to mess with it.
The $871 is what was in my email, too. I should have known that this was a hoax when the "author" insinuated that I'd been visiting "initimate" sites. I am a 72-year old female!
. A fairly boring one at that...