Suggested Reading: Consumer Reports Nov 2015: Lies, Secrets, And Scams-Seniors and Their Families Lose Billions of Dollars Each Year To Heartless Fraudsters. Here, Learn How You Can Help.
Important article to read even if it hasn't happened (yet) to your family member.
As for choice, I can choose not to answer calls from unknown numbers.
The other day Dad said he got a call from a roofing company that they saw holes in his roof. So Dad was quizzing me about that.... told him it was a scam.
When I called Doctors w/o Borders, which from what I've read does provide a lot of charitable work in impoverished countries, I asked them to remove my name, stating that I have no money to give (true). The brassy woman said she would, then asked how often I want to receive solicitations? Duh? Does "I don't want your solicitations" mean something other than that?
My Dad has dementia and I'll think he's talking to an old fishing buddy until I listen very closely. These guys really know how to play it. I've grabbed the phone and told them to takes this number of the list, don't you ever f. Ing call here again, and they're calling again the next day. Luckily I have control of all the finances so not much harm can be done but it's simply amazing what scum is out there.