Of course all your email accounts, social networks, cloud services and payment details are up for grabs if someone grabs your laptop while it's logged in—because, really, we're all to lazy to log-in over and over. But at least your drivers are safe!
Today's XKCD was a real treat to wake up to, but best of all was the mouse over:
"Before you say anything, no, I know not to leave my computer sitting out logged in to all my accounts. I have it set up so after a few minutes of inactivity it automatically switches to my brother's."
It's serve him right for switching the language setting on your phone to Arabic all those years back, right? [XKCD]