Just got one too, same story.  I screen unknown calls to voicemail, and no msg left usually means spam caller.

Same experience as the others - I didn't answer, and they did not leave a message.  I called the number back and got a weird "busy" type signal - doesn't seem like a real number, so you will not be able to block it, unfortunately.

Usually ignore unknown numbers, but answered today.  Gruff voice identified himself as working for some contracting company, following up on an estimate from a few months ago. He just talked his way thru his whole spiel, how they were doing a special, and waiting had saved me 30%, blah blah blah.  When I finally got a word in, I told him he was mistaken, I had no projects in the works and no previous contact with their company.  He responded that he was working from someone else's notes, why would he make this up?  I then got a little snarky and asked, "Why would a salesman make something up?" to which he responded, "I think the problem is you're a f**king retard", at which point I just hung up the phone.

Caller ID name is seemingly meaningless string of numbers following the letter "V":  V52712010000003.

Was expecting a call and accidently answered the call from this number. On Do Not Call list since inception, and generally ignore telemarketer calls.  Like noted by Brian, identified as calling on behalf of some contractor (said business name too quickly to understand) and was told they were offering free estimates for any projects I might have at my house.  Caller quickly hung up when I interrupted and said I was not interested.

Another unethical business/telemarketer ignoring the DNC laws...

Got this call today. Get a lot of them. I do not answer anymore. Man on other line said: "Hello, is (my name) there?" and that was it, no message nothing. Glad I didn't answer. I feel harassed by all these callers everyday. Go AWAY! I am on the do not call list.