Telemarketers are trying to earn a living, and a very unpleasant living it is. When they get through to me, I just hang up and let them get on with their job. I guess if you are the kind of person who pulls the wings off of flies, you can practice on them. But I'd think, you would not want to make a telemarketer too angry, because he/she knows your phone number and might give you another call, say, around 3:00 a.m. Something to think about, anyway.