Thats why it would make more sense to create a list (not a custom extension), and host that list outside of github on a non-US server, where DMCA takedown notices can just be safely ignored.
i think that has the bad side effect of not disputing invalid DMCA takedowns. Instead, we ought to be fighting these invalid DMCA takedowns, and increase the cost of making a false claim. In aggregate, it will make DMCA less abusable, but will require a tough fight. Making bad press for companies that make false claims won't hurt either.
Moving information to outside the US juristiction will only allow abusers to continue to harass those who can't move out.
