Sa company ka nag-dl ng mga movies? then after saving it in your HD, biglang nawala? If you're in the IT fields maybe you're familiar with the Next Gen Firewall (Cyberoam, Sophos, etc). Kung may setup na ganyan sa company nyo, I guess that's the reason.
Isa sa feature ng mga Next Gen Firewall is to restrict users from taking out files of the company and bringing it home, if your workstation was protected by sophos, cyberoam or the likes, ultimo Microsoft Word file di mo mabubuksan sa pc mo sa bahay dahil nilalagyan yan ng encryption. Applicable ito lalo na sa mga USB Flashdrive and external HDD, akala mo nakopya mo na yung files, then pagdating mo sa inyo, di mo mabubuksan yan.
Just my two cents, as far as i know, that may be the case.