Mitch: These "nothing else to do" people do not use the lists. Their equipment is VOIP robo callers that run on a programmed bank of numbers such as 505-505-5050 and 1,000 numbers up and down from that. Their calls are placed to find "valid" numbers. So if the call is answered then that number is added to another list of valid active numbers and sold with the thousands of others to more people with nothing else to do during the day but bother honest folks who are trying to work.
Caller said they were calling from Google Web Services and started asking several questions about an obsolete business name I've not used in 15 years. I asked them to verify their phone number and business name and state why they were calling. The connection suddenly went dead.