[Ipstenu (Mika Epstein)]

You have three possible answers to who ‘someone’ was.

1) You (unlikely)

2) Your client (who figured out how to screw himself up – always a possibility)

3) Someone else using unauthorized methods (be they hacks or using a computer you didn’t fully log off of)

I think that’s pretty much it… Speaking as one who has served her time on Hell Desk, the simplest reason why is usually the right one.