It's been a weekend for catching up on the paperwork - I had to clear some space on the kitchen table somehow.....
Anyway, I opened my mobile phone bill yesterday to find a letter from them saying they were switching me to online billing. All well and good, until I got to the bottom of the sheaf of paper they'd sent me and found another letter, addressed to somebody else, giving the same information. This letter contained this person's name, address, mobile phone number and log-in details for their account on T-Mobile's website. Had I been of criminal mind, I could probably have done quite a bit of mischief with that information.
What I did do was ring the person up and let them know what had happened and we will both be making separate complaints to the Information Commissioner.
Maybe he will be able to make T-Mobile take this seriously. The person in their call centre who I spoke to yesterday really didn't seem to care that much.