I was going through some literature on managing OS X laptops and asked someone some questions about usage scenarios when using the MacBooks. I asked someone more knowledgeable than I about whether it was possible for my Mac to be taken over if I were visiting another site for a conference or if I went on a wifi network at a local coffee house with policies from an OS X Server with workgroup manager (either legit for the site or someone running a version of OS X Server on hardware they have hidden somewhere on the network), which apparently could be set up to do things like limit my access to Finder or impose other neat whiz-bang management features.

He said that it is indeed possible for it to happen as it would be assigned via the DHCP server and the OS X server would assume my Mac is a guest and could hand out restrictions and apparently my Mac will happily accept them without notifying me or giving me an option, unlike Windows which I believe would need to be joined to a domain before it becomes "managed" by Active Directory.

So my question is as network admins and sysadmins with users traveling with MacBooks, is there a way to reasonably protect your users from having their machines hijacked without resorting to just turning off networking all the time? Or isn't this much of a security hazard? What threat does this pose to the road warriors in your businesses?