I was just notified that I received the Vox Populi badge on Super User, which is apparently awarded for voting 40 times in a single day. I don't vote nearly that often (I average about vote every 2 days), so I can't fathom that I ever made 40 votes in a single day. Especially not yesterday or today, since I did almost nothing at all on the site either of those days.

Is there a bug in how Vox Populi is calculated that caused it to be awarded to me in error?