One of the most valuable things I learned in my career was to never kick your competitors when they are down. It upsets the karma gods, and makes you look like a total douchebag.

The best thing you can do right now is to reach out and offer your help, privately. Even from a selfish perspective, you'll learn a lot about the attack that is taking them down now which will help you out when the targeted customer inevitably signs up for your service.

EDIT: The parent comment was spam from Kris Beevers at NSone.