I have had to resort to a practice that I vociferously objected to in earlier years. Call screening.
I don't answer the telephone unless I recognize the number. If someone doesn't leave a message, then they didn't want to contact me. What a shame to have to live that way.
The real shame is that probably 50% of the callers work for soliciting organazations and really need the job to survive.
What we know is that most programs are not able to handle exceptions very well, so the test would be to pass the caller some exceptions. I get calls about cars and credit cards, I ask if it is about the Ford pickup or about the Corvette, or the master card or the discover card. I have none of them, so they are always unablke to answer correctly. That always trips them up.
The worst part is that I am on a do not call registry, and so some of them do disconnect before I can say anything. But others keep calling no matter what. I will need to try that technique mentioned by one responder and see what happens.
I know someone who DID give them what they wanted (yeah, there's some dummies out there) and their computer had to be reloaded from scratch. I guess if they get into one in a thousand PCs they get what they want. As I recall the person had to change all their passwords but didn't lose any money, fortunately.
Yeah, I got a call from them at my parents' house in the USA. I asked THEM what IP address they'd found the virus on and of course they couldn't answer and went back to a random place in their script. I was able to waste quite a bit of their time.
Here's the punch-line, in two parts: (1) My parents don't have a computer or Internet connection. (2) I was talking to them on a Western Electric dial telephone.
@DrQuine....we also have a Do Not Call register in Australia (politicians are of course exempt :-) but it does not stop the guys phoning from India purporting to be from the "Microsoft Computer Centre" advising you that your computer has a virus and trying to phish your IP details from you so they can "fix it" (yeah right).
If they're male I question the size of their anatomy, and if they're female I treat them like a phone sex line. Usually gets rid of them pretty quick and sometimes give you a bit of fun in the process.