I SOLEMNLY SWEAR I AM UP TO NO GOOD
Despite the ‘up to no good’ portion, this map was created with the best of intentions. Sure, you can be nosy and see where everyone is in the wee hours of the night, OR you could help your friend cursed with lycanthropy find a place to ride out the night. See? Hearts of gold. Hearts of gold lined with lots of pranks aimed at Severus Snape. But hearts of gold nonetheless.
Keep tabs of everyone in the everyone in the castle. And we mean everyone. It might act up from time to time and say Peter Pettigrew roaming around, but that just is a mistake, right?