But to go back to what someone else said in another thread, when Warner Brothers is asked if they're sure, and they answer yes, it becomes admissible evidence of a higher level of culpability. Knowing no other facts, a bad takedown could conceivably be the result of conduct that doesn't even rise to the level of negligence--maybe someone got bad info somehow, maybe someone copied all the torrents linked from a page that contains a dozen Transformers torrents, and inexplicably, one for Ubuntu. I can see a jury of reasonable men accepting that with the sheer volume of piracy WB has to deal with, its agents can still make mistakes even when exercising reasonable care.
The counter notice changes that. It's like the difference between an author making a typo even after a round or two of self-editing, and an author getting an marked up draft from his editor with a big red circle around the typo in question, and still not fixing the typo. The counter notice is a big favor to WB, it's a warning to pay extra attention to a specific issue, and WB, by responding Yes, is either saying "We looked again, and this Ubuntu torrent actually contains a terrible movie," or they're saying, "GTFO google, we don't actually care to check our work." At this point, it would be hard for WB to argue that its agents weren't extremely reckless, if not acting intentionally.
Sending the counter-takedown may not get immediate results, but it will yield a treasure trove of useful evidence for anyone with the standing to sue or to trigger relevant enforcement actions under the DMCA or related laws.
Very well said