The other side of the coin is that even if they aren't receptive to the scams, they stop answering the phone as much, which contributes to them losing even more

The other side of the coin is that even if they aren't receptive to the scams, they stop answering the phone as much, which contributes to them losing even more contact with people. I have a half-hearted Asterisk setup. When my dad was alive, I set up an Obi110 hooked up to the phone line. I created a whitelist of numbers of family and friends. Anything not on the whitelist was answered by Asterisk, the SIT tone played, and then a message "please try your call again". Its CID was then stored in a one-entry database "greylist" so that a subsequent call from the same number would ring normally. The sheer majority of telemarketers don't call twice in a row. When I set it up I actually fat-fingered my uncle's number on the whitelist. He got the "error message" and dutifully called right back, so I felt pretty comfortable that the system wouldn't fail terribly. In general it's a thorny problem, especially when both parents are alive as they'll generally enable each other by insisting that business as usual is fine. Knowing what I know now, I'd try to push in harder to make changes that needed to be made, but it's so much easier said than done.