Slighty concerned!

fwor

I don't know the browser that BT bundle with their service, but it's probably just a "badged" version of IE. None of the browsers that I've used recently let the user list previously stored passwords - they are typically stored in an encrypted file which the user can't access directly.

That's not to say that it would be impossible to crack the encryption on a browser password file - but it's hard to see why a BT employee would consider doing that, given that snooping around a customer's PC for passwords is undoubtedly a disciplinary (if not sackable) offence within BT.

Whatever the explanation, if your father sees any other suspicious activities that can be demonstrably linked back to BT staff, he should raise the issue directly with the BT internal security investigations department, which has a very good reputation. Also, if I were him I'd change all my passwords, and store them in Keepass - so he can make them as random as he likes without having to worry about forgetting them.