Along with that OT re scam about tech support, remember that if someone you don't know calls and asks "Is this Mr. Concerns" or whatever your name is, DO NOT ANSWER YES. They have started digitally editing people's voices saying "YES" into supposed agreements to allow recurring charges, etc.

When I get those calls, i often say calmly but actually what I say is rude:
"What do you want" or, if I'm pretty sure they're selling something, "What are you selling?" That has the dual purpose of NOT saying yes, and throwing them off the script.

Then I tell them to put me on the Do NOT CALL list. If they apologize, I know they are a "legit" phone seller. If they say something nasty or slam the phone down, I know that someone in Nigeria is angry, and that makes my day