
An effort was made to remove the sticker.  It came to pieces, leaving
most of it firmly attached to the window.  It was dark, and around
10:00 pm.  The sticker (before being mangled in an ineffective attempt
to be torn off) warned the car would be towed if not removed.  A
"reasonable person" would arguably have driven the car.  Had an
accident occured, I don't think my friend's attorney would have much
trouble fixing blame on the apartment mangement.

As a practical matter, even without a conviction, the cost and
inconvenience of defending against the suit would be considerable.

As a moral matter, it was a pretty fucking stupid thing to do for so
paltry a violation as parking without an authorization sticker (BTW, it
wasn't "somebody's" spot, it was resident-only, but unassigned,
parking).
