On 3/8/20 9:59 AM, Damian Menscher via NANOG wrote:
In the robocall case, there*is* something the end user can do to fight the abuse: answer every call, and keep them on the line as long as possible. They are paying for connected calls, for the connection duration, and for the humans to scam people. If everyone tarpitted them, the business model would fail.
+1 When I recognize the name and number on caller ID, I'll answer in the usual manner. I answer calls when I don't recognize the name or number, but say nothing. The caller then drops the connection, usually in 10 seconds -- and I hear the disconnect -- and usually my cordless phone's base station notices the disconnect as well. (Yes, I still have a standard POTS line.) What if it's an unknown person but otherwise valid and not robo-call? They will notice the ringback tone stopping and will say "Hello, hello?" at which point I can have a conversation. (Some robocallers will notice the ringback tone stopping and start their automated spew, at which point I press "Off.") This helps keep my blood pressure low, keeps my answering machine from filling up with useless calls, and I feel good that someone just spent a nickle for nothing.