These are the DC Comics Batman Silhouette Tights available from Hot Topic ($12). They also have bear, bunny and cat ones that have the animal asses on the back of the tights. I thought that was a nice touch. FUN FACT: for every man who's ever waved a gun around robbing a bank with a stocking on his head, there was a man 12 hours earlier that was either rummaging through the J.C. Penney hosiery department or a girlfriend's underwear drawer. That's weird to think about.
Keep going for shots of the animal ones, including the suspicious looking bear.