An aside:
On Wed, 2011-01-05 at 11:12 -0500, Adam Jackson wrote:
(And of course what we're doing here is protecting against a malicious attacker who already has enough privileges to run code on your system, which means you're pretty far into having already lost. Meh.)
I've seen this viewpoint a number of places. IMO, it's a shame that the community seems to be giving up on local system security. In various situations, it would be quite convenient if I could give other people shell accounts on my machine without risking compromise of all of my data. The virtualization solutions are more work to set up. If what you say is right, the many schools that still use large shared shell servers are relying on their users not to be too evil, or alternatively the users shouldn't use the servers for anything important.