Bet it was Sky. The email account security for them is the worst.
Having once worked for them, I had a customer who was complaining because when he logged int his account for the first time, he was forced to reset his password, and found 24,000 emails dating back several years. Which he had proceeded to delete.
He had been a sky customer for 10 days.
He had actually accidentally hacked another users account because they shared a name and taste in football teams.
He did not want to accept the fact that he had broken the law. He was also unhappy that some other person kept trying to change the password back again.
My forehead met the desk several times over that conversation before i passed the whole mess over to a manager to escalate to the appropriate people.