Also remember that while sometimes its your friend who is on vacation, all that has transpired may not be being shared. Have you seen "To Catch a Predator"? You know where the person is 'Oh, I just came by to say hi' - then the rest of the stuff starts showing up.
Ironically, that happens in IT as well.. clients tell me "Oh, well I was just reading email" and it turns out that they also were doing some other stuff and just installed program XYZ.
Ironically, that happens in IT as well.. clients tell me "Oh, well I was just reading email" and it turns out that they also were doing some other stuff and just installed program XYZ.