In the wake of the recent digital certificate hacks, Mozilla is not taking any chances, and has asked all companies that issue these certificates to be on high alert for suspicious activity.
Specifically, the browser maker wants all Certificate Authorities (CA) to complete a series of security checks by September 16 to make sure they too won't fall prey to a cyber attack like the one that hit DigiNotar. The requests are mostly technical in nature, but basically boil down to: Have you been hacked? Are you sure?