I do remember entering a negative number one week on the manager's "status spreadsheet (an excel spreadsheet on a network share that he asked everyone to edit)" next to my name. Of course he came by asking for an explanation, and if memory serves had me enter the number of lines deleted as a positive number, so that the 'metrics' he reported up the chain didn't look bad.
http://www.folklore.org/StoryView.py?story=Negative_2000_Lin...