Retaliation.

Having broken free from captivity by this well-dressed gang, the unmasked Batgirl decided to take the initiative and take down her captors. Even if they now know for sure that Batgirl is Barbara Gordon, she's going to make sure that their capturing and unmasking of her will be the biggest mistake they ever made, as even after being put in a disadvantage, in Barbara's heart, she knows that Gordons don't quit, and that Batgirl's true power doesn't come from the anonymity provided by her mask, or even the gadgets from her utility belt (that she just retrieved from their possession, but nevermind that).