Here is a call that the caller ID identifies it as:  SYNOVATE
I do not pick up the calls when someone I don't know is calling.

If by chance I happen to pick up the phone and answer a call of someone soliciting, or trying to get my opinion about something or anything else, I always say in a very nice way,"  I sorry..it is my policy not to give our personal information on the phone"  They politely say "I understand" and then hang up.  

One time I got calls like this and I got really angry and told them never to call me again.  That was a big mistake....They kept calling and calling and calling....then it stopped.