It's possible to steal an identity with only partial information. The craft of "blagging" is used, a mix of psychology along with good knowledge of how security systems work in many CS departments. "Blaggers" seek to convince the CS agent that they are the person to whom the information belongs, but need a little help because something that SHOULD work does not. The aim is to get the CS agent to let further information slip out as they believe they are dealling with the correct person. This extra puzzle piece makes each step in the "blagging" process easier. In the end, they have all they need to do some SERIOUS damage. Instances include:-
1) You go away (has to be extended holiday), and find an ID thief has sold your own HOUSE, and made off with the proceeds.
2) Credit taken out in YOUR name, YOU are chased for repayment, your credit history is trashed, wrecking YOUR chances of getting ANY kind of credit, INCLUDING a mobile phone, gas, electric supply under "normal" terms etc. (This is the common one, it is lucrative, and pretty easy once all the information has been gathered). It is worse if you have a history of regularly moving home.
3) Illegal entry into the country on YOUR passport, although this is getting progressively harder. Normally, they DON'T just copy the image, they pass the INFORMATION within it to an expert passport forger, who uses it to forge a near perfect passport with all YOUR info, but the PHOTO of the illegal entrant. BIG MONEY changes hands for illegal entry into the UK, and a forged passport, although not cheap, is NOT anywhere near the biggest expense an illegal immigrant is fleeced out of by the people traffickers who make all the big money.
4) Confusion caused by identity theft can run deep, it can even result in national databases becoming corrupt, and remaining so for many years. There was a case featured where duplicate UK National Insurance numbers were issued. Normally, these are issued at birth, and remain with you for life. If you are "cloned" this way (someone else uses your number), you can actually cease to exist in true Orwellian 1984 style, with the clone becoming the "genuine article". This happened with the case featured, withy BOTH persons insisting THEY were the true holder of the number, and once the authorities made the decision as to who was right, the other person was erased from database history. This was particularly galling, since the authorities had got it wrong, and it was the "clone" that "survived. It was sorted out in the end, but it revealed this was NOT a "one off", and one main source was people with SIMILAR names getting confused, so just imagine what someone using your EXACT details could do!!