When you hear about "piracy" in connection to YouTube, perhaps you think of the billion-dollar lawsuit brought by Viacom against the Google division, claiming that Google should have the duty to police all of its users' uploads to determine that they don't infringe copyright.

Google does something very close to this already, of course: the company offers a service to rights holders called "ContentID" that is meant to automatically police copyrights on their behalf. Rights holders upload copies of their copyrighted works to YouTube and identify themselves as the proprietors of those works, and YouTube scours its files for videos or audio that appear to be connected with those copyrights.

Rights holders get to decide what happens next: they can ask Google to automatically remove matching files (Google then notifies the user that her files generated a copyright match and offers them the opportunity to contest it), or they can "monetise" the video by asking Google to display ads whenever it is played back. The revenue from these ads goes to the rights holders.

ContentID does a lot more than US copyright law requires of rights holders. Under the US Digital Millennium Copyright Act of 1998, services like YouTube enjoy a "safe harbour", that shields them from liability for copyright infringement. In order to maintain this safe harbour, YouTube must "expeditiously" respond to notices of copyright infringement by removing the offending works. But the law does not require YouTube to proactively search for infringements and remove them. Running ContentID isn't a legal duty, it's an olive branch extended by YouTube to the audiovisual industries.

ContentID is contentious for many reasons. Viacom says it doesn't match enough of its works, and complains that it shouldn't have to tell Google which copyrights it owns – Google should just figure this out and block Viacom's works a priori.

But one titanic problem with ContentID has received little attention: the use of ContentID by those who falsely or incorrectly assert ownership over public domain works – works that have no copyright at all – and then either block access to the videos, or collect the advertising revenue from these videos.

FedFlix is a charitable project launched by Carl Malamud, a "rogue archivist" who raises funds to digitise and upload videos created at US government expense. Under US law, government creations are in the public domain and can be freely used by anyone, but the US government is remarkably lax about actually making its treasures available to the public that owns them.

Malamud's group pays the fees associated with retrieving copies from the US government – sometimes buying high-priced DVDs that the government issues, other times paying to have unreleased videos retrieved from government archives – and posts them to YouTube, the Internet Archive and other video sites, so that anyone and everyone can see, download, and use them.

Malamud's 146-page report from FedFlix to the Archivist of the United States documents claims that companies such as NBC Universal, al-Jazeera, and Discovery Communications have used ContentID to claim title to FedFlix videos on YouTube. Some music royalty collecting societies have claimed infringements in "silent movies".

These companies' claims – there are hundreds of them – have the potential to generate black marks on FedFlix's YouTube account, and these black marks could lead to automated punishment from YouTube. Accounts that generate claims can be suspended or deleted, or lose the right to mark videos as being available as Creative Commons or public domain files.

YouTube offers very little help for FedFlix. ContentID's dispute resolution mechanism allows FedFlix to contest these claims under only three circumstances: first, ContentID has generated a false match (that is, the video isn't what ContentID thinks it is); second, the uploader has the right to the file, as demonstrated by written permission from its proprietor; or third, the use is acceptable under the US doctrine of fair use, or its counterpart in other laws, fair dealing.

But FedFlix can't contest on any of these bases. ContentID isn't mistaken – the files are exactly what ContentID thinks they are. But no rights holder can send a written permission notice to YouTube about these files, because they have no rights holders – they are in the public domain. The posting of these files isn't "fair use". Fair use is a copyright infringement that is lawful because it serves some allowed purpose. FedFlix's posting of public domain files is not a copyright violation, so they can't be fair use.

Malamud's report documents these troubles in Kafkaesque detail. It's frustrating reading. The American public paid to produce these videos, and they own them, lock, stock and barrel. Multinational companies – the same ones who cry poverty and demand far-reaching laws like the Stop Online Piracy Act – have laid title to them, "homesteading the public domain", and they are abusing Google's copyright peace offering to steal from the public.

And unfortunately, there is no organised lobby for the public domain to demand the kind of stiff sanctions for Universal and co that other copyright infringers face at their behest.