I'm guessing that the vast majority of people harmed by false DMCA takedown notices either do nothing or, if they act at all, file a counternotice with the content host and leave it at that.
The problem may not be the absence of available sanctions, but the fact that people don't seek to apply the available sanctions.
I wonder what an "automated DMCA counternotice filing service" would look like?
I wonder if there's some entirely legal and moral way to ensure erroneous DMCA takedowns have non-zero costs involved for the parties serving them (while having as-cloase-as-practcal to zero cost for innocent sites defending against them)?
"If you believe that content residing or accessible on or through the our website (“Services”) infringes a copyright, please send a written notice (by fax or regular mail) to the Designated Agent at the address below. You may not communicate the information specified below by email. Please note that you will be liable for damages (including costs and attorney’s fees) if you materially misrepresent that material is infringing your copyright(s)."
http://arstechnica.com/tech-policy/2012/10/after-five-years-...
That seems to also accurately reflect the most recent action in the case, the order denying both parties motions for summary judgement in January [1][2].
[1] https://www.eff.org/node/73102 [2] https://www.eff.org/deeplinks/2013/01/lenz-v-universal-baby-...
Which means that you must believe what you claim to be true. It doesn't mean there's any penalty whatsoever if what you're saying is found to be bullshit after the fact.