Think of the children!
Another question from the audience today:
Q: I like IE8's InPrivate Browsing feature, but I'm worried that it won't let me see what my kids are up to. Can I prevent them from using it?
A: Yes. When you enable the Windows Parental Controls feature, or use the Windows Live family safety tool, Internet Explorer's InPrivate feature is disabled. The Parental Controls features have the additional benefit of helping prevent the user from simply using a different browser to hide their tracks.
In corporate environments, Group Policy can be used to block access to InPrivate Browsing feature, and the various Delete Browser History settings. Home users can simply run the following registry file: NoPrivacy.reg to block InPrivate Browsing and help prevent deletion of Temporary Internet Files and History.
Of course technology isn't a panacea. As Scott Berkun notes:
Any 12 year old that can’t access porn at his home computer is going to do the simplest thing: hang out at friend’s house whose parents don’t use parental controls.