Question: A long-time client has asked us to help screen their work machines for pornography. They're worried about liability if sensitive materials were found. Their main concerns (for obvious reasons) are video, audio, and image files. If possible, they'd also like to scan text-based documents for inappropriate content. They have a hierarchy of not-for-work content starting with blatantly illegal (I don't have to list details), moving down to obviously offensive, and also including things that may be offensive to some - think lingerie ads, joke cards featuring butt cracks, and anything related to Howie Mandel.

My questions are:

* Is this ethical? I think it is since every employee legally agrees that their work machine belongs to the company and is subject to search. The screenings are not to occur on personal machines brought to work.
* Is it feasible? I've done a lot of image processing/indexing but this seems like a whole new world of complexity.
* Any references to successful techniques for discovering porn?
* Is it appropriate for me to archive the results when something is discovered?

Answer: 
You can do this with 90% [Headology](http://wiki.lspace.org/mediawiki/index.php/Headology), 10% software.

Firstly, quietly scan employees computers, build a database of files and sizes for each employee.

Then leak a memo that all PC's will be scanned for questionable content, i.e. The bosses have a [Shazam](http://itunes.apple.com/ie/app/shazam/id284993459?mt=8) like program that can identify porn etc.

Then a couple of days later, scan the computers for files and sizes again. Look at any deleted files, are they movie or image files? Then those are the employees you need to keep an eye on. 

Routinely scan those employees PC's for images and movies, and manually check them for questionable content.
About legal aspects, in France:

The boss owns the computers and the internet connection: He can do whatever pleases him.

BUT, employee privacy cannot be violated. If a directory on the computer is labelled PERSONAL, the boss is not allowed to scan it.

The only way to bypass that is to get elements of evidence that employee stores illegal material and to get a court request a scan of computer (Note that pornography is not illegal in France.)