Can anyone explain to me why, on a door and frame that are already drilled, routed, etc, for a standard knobset, some doofuses insist on using padlocks anyway?
There are a couple of buildings here locally where they've actually gone to the extra hassle of getting padlocks keyed to the existing masters so they could do this rather than replace a worn out (and old/well used enough to justify wearing out) knobset.
Of course, it's a particular pain in the ass when one needs to get through the door from the other side, and just invites trouble from pranksters if one doesn't take steps to avoid being trapped inside.