Another sanitize Question

I have asked various questions about data sanitization and I came across teknoids blog post about the same subject

 

read it here:

http://teknoid.wordpress.com/2009/08/06/save-now-sanitize-later/

 

I did get the same answer from fellow bakers "no need to sanitize, use h() and see users trying to do stuff they should not be doing".

 

My only question is how do you track users who are attempting to add scripts or what not? If you have a site with say 2000 users making changes everyday how do you possibly monitor each edit? How do you find these users other than going thru everything daily / hourly? Just wondering how would you find such a user easily in endless list of possible users?

 

Thanks,

 

Dave