Beware phone number spoofing scam

http://money.aol.co.uk/2014/03/05/beware-the-caller-id-scam/?

Most frequently this is used in an attempt to obtain your bank details and pin numbers by criminals impersonating your bank/the police/government department.

The scam
The criminals have modified their caller ID to match that of a legitimate bank. The technology allows experts to do this, if, for example they want to leave an 0800 number for you to call back. However, the criminal gangs are using it to their advantage.

Once they have changed the caller ID, they pose as the representative of a bank, credit card company or government department. They'll give a convincing-sounding story and then ask for account numbers and other sensitive information.

There are other ways it could be used.