Many people perpetrating unsolicited telephone calls decide to use cell phones for the simple reason that cell phone numbers are unlisted (unpublished or unregistered). However, that does not mean that cell phone numbers should be considered immune from unwanted and anonymous calls - far from it. Telemarketers, stalkers, prank callers, creditors, and many others could be harassing you under the false assumption that you cannot track them based on the fact that their cell phone number is unlisted. Their assumption is false because, thanks to the internet, you can now discover precisely who owns the particular cell phone number that has been calling you.