For your digital work to be protected by copyright you need to actually own some documents. If you want to action someone in instance the "Copyright 2020" text from your website doesn't mean anything. Even EULA is not recognized by EU or US. If you clicked a checkbox that says "I have read the terms and conditions" and in the terms says copyrights, doesn't mean that it is actually protected. Large corps entities like Microsoft, Google, etc actually owns the copyrights and have some documents proving. But let's be honest I don't think Minecraft modders tries to get the rights for their works. They placed © All Rights Reserved just to scare people who tries to decompile it. A lot to companies just use the user's naivety to protect their work. Even Mojang had not rights on Minecraft before being acquired by Microsoft.