People trying to register for Bluebikes accounts right now are can't, because the app is dead, something about servers or something. Bluebikes reports it's aware of the problem (not surprising given that @RideBlueBikes on Twitter is being barraged with complaints) and is telling would-be riders:
We appreciate you reaching out to report this issue. Our engineers have already been notified and are working on a fix as we speak. Thanks for your patience and understanding.