SELinux is a permission system, which works on top of the well-known UNIX user/group system, but allows a much finer resolution for who's allowed to do what. Those who have installed recent GNU/Linux distributions are likely to use it, possibly without knowing about its existence, wondering why some operations fail for no apparent reason.
Unfortunately, today's existing documentation is very tricky to follow, putting a significant barrier in front of anyone who wants to configure this powerful security tool.
This double lecture is a hands-on tutorial, focusing on what one needs to know in order to tie the hands of a certain application. As a side benefit, it will make the existing documentation significantly more readable.
Audio recording of the talk (part I)
Audio recording of the talk (part II)