I answered and spoke with a man named Jack who spoke with an Indian accent.  He indicated that he was from "Windows headquarters"  and that my computer was sending several error messages and that he was calling to help me as my situation was urgent.  I told him that I didn't have any computers running Windows (as I'm sure he's running some kind of scam) and he hung up immediately.

I answered but it was just background noise on the other end. I hung up after a couple seconds, assuming it was a telemarketer waiting for me to answer.

Called and left no message on my voice mail.  Surely much more could be done to track down the people making these calls and to shut down their operations and to prosecute and convict them.