Comment by JuniperMesos

Torrents can be used to spread information that is in the public domain or licensed freely, just as much as they can be used to spread copyrighted information. Obviously most of what people actually use torrents for is pirating copyrighted media against the wishes of the copyright-holders, but that's not inherent to the protocol.

Nitter instances by contrast are specific software intended to view information on a specific proprietary social media website in ways the owners of that website don't want them to. It's a question for lawyers if X declaring this to be a type of copyright violation will hold up in court, but X is also actively trying to block Nitter instances from accessing the site at all, which is a technological rather than legal mechanism.