Re: Not all that useful...
SELinux isn't new technology; it's at least a decade old. It is is badly designed and poorly documented technology though.
The point I was making, however, is beginner Linux admins ought to turn off SELinux because they'll try and do something simple and it won't work because of SELinux. There are other things they could do which aren't mentioned in this article which will make their systems more secure anyway and won't be such a pain-in-the-arse.
For one, CentOS has a stupid amount of services running as default, most of them ridiculous. If I remember correctly, one is a bluetooth service or something mad like that. The first step to securing a box is to stop unnecessary services. Another is not to run Webmin which, If I remember, has had some pretty nasty vulnerabilities in the past.
There are indeed thousands of Linux boxes directly on the net. In fact my personal server is. But when I say serious, I mean serious as in "Let's hire a sysadmin to look after this" type serious. I would expect at least a screened subnet type network setup for running a serious network system, whether Linux or any other OS. Not only does it aid security, but allows you to move from a server that's a single point of failure to something more highly available.
The conclusion is of course that this article is aimed at hobbyists rather than people employed as a sysadmin, therefore SELinux would be a hindrance.