I just ran into a nasty little problem on my campus network. Someone in the lab I take care of enabled Internet Sharing on his computer. This of course fired up a nice little DHCP server built into OSX and started handing out IP addresses to anybody who plugs into the campus network. This is bad. It does not make the IT people happy, and they cut the entire lab off the network. A few phonecalls and I eventually found out what had happened and turned it off, but now I'm wondering if there's a way to permanently disable that feature in OSX, to prevent anybody else from accidentally turning it on. I could obviously just lock the System Preferences application, but that locks down Energy Saver and a couple other preferences people will want access too. They also have admin privleges on their own machines, so they could unlock it if they felt like it. And yes, I can of course just tell people not to check that box, but a more permanent solution is always preferable, and makes the IT guys happier--they're not huge Mac fans, despite this being a university with a reasonably large Mac presence.