I get them all the time some times it is only like 3 or 4 numbers too. I ask my cell phone company and they said it is telamarketers. If you try to call the number back it will give you a message of some kind.

Either Telemarketers or Voice Over IP (VoIP)(Which is basically a computer to phone call with a service such as Skype or Yahoo!). I know my VoIP often comes up on caller ID's as 0-123-456-7890. :)

It either means that the caller didn't want to provide the actual number or was unable to. There are two ways that name and number information is transmitted with a phone call. The one that shows up on your reader is the newer type that we think of as caller ID (CID). The older type is called Automatic Number Identification (ANI). Obviously, CID isn't always accurate. Many companies have a telephone switch on their premises to meet the needs of their phone system. This switch is not controlled by the phone company and it is the customer's responsibility to program it. One of the settings they have control over is the name and number that is displayed on CID units. Often, this is used to display the company name and official 1-800 phone number on every outgoing call rather than Joe Employee's name and the direct number to reach his cube. Telemarketers take full advantage of this because they know that nobody would pick up if the CID warned that it was "Sell You Crap During Dinner, Inc." I hadn't heard of Voice over Internet Protocol (VoIP) calls displaying bogus information but it makes sense. Calls over the Internet and over the traditional phone network are very different at their most basic nature. While they work together, it is essentially two different native environments that have been made to work together. The calls get converted at the point where it switches from traveling over the Internet to traveling over the Plain Old Telephone Service (POTS) network. If the VoIP company can't or won't provide proper CID information, they still have to provide something for the conversion to go smoothly. ANI is the other method of providing name and number information. It cannot be changed in the same manner as CID and is considered to be more reliable. Some companies provide ANI access to residential customers for a fee. http://en.wikipedia.org/wiki/Caller_ID http://en.wikipedia.org/wiki/Automatic_number_identification With regard to telemarketers hanging up before you can get the removal request out, I have never been hung up on. I always say, "Please put me on your do not call list." I think it may work better because it sounds like it could be positive. I also am registered on the national do not call list and rarely get those calls to begin with. https://www.donotcall.gov/default.aspx