unknown caller

Second call I received from this number. No message was left on voice mail. When I call the number I received a message that the number was not in service.....Hmmmmmm I'm assuming the caller has a way to provide false Caller ID information....similiar to masking your IP address on the internet. Anyone know if that's possible with telephone numbers?

BTW I never answer calls when I don't recognize the number. It can't be legitimate business or friend because they would leave a message!

Calls twice a day without fail! call back and get same response that phone is not in service. I don't answer unsolicited calls but am tempted to answer this one,just once.

I got several calls from this # before and they did not leave a message.  Today I finally answered the phone and it's an automated message about a carpet cleaning service.  I hung up before the message was completed.