Not perfect, but it does make a pretty big disincentive to being caught issuing fraudulent takedown notices.
For example, according to <http://www.techdirt.com/articles/20090315/2033134126.shtml..., Google has stated that 37% of the takedown requests they receive are fraudulent.
edit: Why does Hacker News not support <scheme://path> (with brackets) syntax? It's nothing new.
In theory, perhaps, but in practice I can find many false notices. The EFF even keeps a "Wall of Shame" with the worst notices: https://www.eff.org/takedowns
A tiny number have gone to court, but even then, damages are rare. Diebold is the only company I can find that has paid significant damages for false claims. While several courts have made rulings of bad faith, I was unable to find even one perjury conviction over a false DMCA notice.
Here's the actual text of the DMCA (HR 2281) [1]:
> A statement that the information in the notification is accurate, and under penalty of perjury, that the complaining party is authorized to act on behalf of the owner of an exclusive right that is allegedly infringed
You are only swearing, under penalty of perjury, that you're the owner of the copyright or authorized to act on behalf of an owner of the copyright. You are not swearing that you believe an infringement has occurred, or to anything else in your notice.
Thus even if you know the other party is not infringing your copyright, you are not committing perjury by attesting that they are infringing to a service provider. I don't know if there are other consequences of false takedown notices, but the swear under penalty of perjury doesn't actually exist.
> (f) Misrepresentations.— Any person who knowingly materially misrepresents under this section—
> (1) that material or activity is infringing, or
> (2) that material or activity was removed or disabled by mistake or misidentification,
> shall be liable for any damages, including costs and attorneys’ fees, incurred by the alleged infringer, by any copyright owner or copyright owner’s authorized licensee, or by a service provider, who is injured by such misrepresentation, as the result of the service provider relying upon such misrepresentation in removing or disabling access to the material or activity claimed to be infringing, or in replacing the removed material or ceasing to disable access to it.
You can't copy code and tweak some stuff and call it your own.