A flurry of reports have surfaced around the web explaining that even an accidental login to one’s Guest account within Snow Leopard could lead to mass deletion of all user files on the primary account, and when we say “mass deletion,” we mean “mass deletion.” The problem goes something like this: if one clicks on the Guest account after upgrading their machine to OS X 10.6, and everything hangs, there’s at least a decent chance that all of your data will be evaporated whenever you surf back over to the main profile.
I’ve heard whispers about this for a week now — it’s a serious bug, but it doesn’t seem to be an issue on every system. Still, better safe than sorry — I just turned off the Guest account on my MacBook Pro.