This is the best most comprehensive article written on this subject. And there is a link to every other article. As usual EFF does their homework and applies their judgement to describe perfectly:
The heart of this fight is for what Reddit’s CEO calls their “valuable corpus of data,” i.e. the user-made content on the company’s servers, and for who gets live off this digital commons. While Reddit provides essential infrastructural support, these community developers and moderators make the site worth visiting, and any worthwhile content is the fruit of their volunteer labor. It’s this labor and worker solidarity which gives users unique leverage over the platform, in contrast to past backlash to other platforms.