I'm curious who has standing. One of the people who posted/commented in the original thread? A user who wanted to learn about CipherCloud? StackExchange itself?
Actually, is a DMCA notice against something that's fair use technically bad faith? You are still violating their copyright, you just have a defense against it in court.
Ultimately, whether something is fair use or not is the purview of the courts. Does the DMCA require you to make that judgement before submitting a notice? I would guess not.
And unfortunately, you can't sue people just for being jerks.