I have just spent the past hour composing a letter to Tiscali customer services.
I have only been a customer since April, but in the past week I have recieved 2 emails from customer services intended for other people and including other customers' personal information (including a password, in one of them).
I have contacted them about the first time it happened (6 emails so far... 3 replies) and they are denying responsibility, claiming that someone is trying to use my account fraudulently (despite the personal info involved). I emailed the other customer and she has a daugher with a similar email address to mine.
I am horrified at how careless and completely incompetent they seem to be. I think their customers should be made aware.