Not difficult at all, but the counter claim has to come from the owner of the github repo, not just anyone.

And we don't know what is in the mind of the repo owner, so we have no idea why no counter has been filed.

DMCA counter-claims require the name, address and phone number of the repo owner which is why fake DMCAs are a well-known method of doxxing anonymous people.

The DMCA is a very flawed law that is easy to abuse and isn't even effective at stopping actual copyright infringement from being rampant on the internet.

My understanding is that you can sue for damages if somebody makes a fraudulent DMCA claim but that's not a sufficient deterrent because lawsuits are expensive and often the damages are small or non-existent. For example, it almost certainly wouldn't be worth it for the owner of this repo to sue the MPA (if an actual attorney disagrees, then I defer to their opinion).

For the MPA, this DMCA is all upside and no risk even though it seems legally dubious. For the repo owner, a counter-claim is a self-doxx that opens up the risk of being sued by the MPA (if they think it's actually worth suing over) for very little upside. Which is why this is such a good example of why the DMCA is a bad law.

While the DMCA isn’t a perfect solution, the absence of the DMCA would have worse consequences. In that case, the reality at best would be that GitHub would simply take your content down with a C&D and you’d have no opportunity to challenge it. But highly likely that GitHub wouldn’t legally risk themselves to host others content, and it just wouldn’t exist.

> DMCA counter-claims require the name, address and phone number of the repo owner which is why fake DMCAs are a well-known method of doxxing anonymous people.

Can this be a business?

A named individual has to "sign" both a DMCA notice and a counter notice.