Only an idiot would have had to miss the skeptical that was the Joker walking down the street. A nerve struck in her mind, hearing the song that Joker had posted on those computers. Or close to the same song, but it seemed he was making up more as he was going, or adding more words. As far as she knew the Joker either a) didn't know she existed, or b) knew there was a Batgirl, but didn't know her actual relation to Bruce. Either way, she was about to become a little more known.
Her bike surged forward, picking up speed until she had the Joker in sight. Even if she missed the face, the clothes, and the off pitch singing, she couldn't miss the people moving quickly to get away from him, or running scared.
Once near him, she slammed on the breaks, maneuvering the machine and sliding to a stop that brought her only about ten feet from the psychotic clown. Batgirl glared at the clown, a distinct frown visible through her skin tight mask.
"You're way off tune." she informed him. "I'm not sure what's worse, your voice, or the terribly lyrics." he'd wrote a song about killing Batman and Terry. It was more than a little disturbing.