Traditional media could review content because it oversaw production

Evidence

Editorial review of platforms is most similar to the ways traditional media handle offensive content. Of course, traditional broadcast and publishing media have the advantage that they typically oversee the production of that content before it ever reaches their audience. Television shows are commissioned and produced, news articles are assigned and filed. Even independent productions, be it a television pilot or an unsigned demo recording, have to be brought to the distributor for consideration. For U.S. films, for example, the MPAA ratings board is charged (by the major studios) with imposing its ratings system on all films slated for U.S. release. — Tarleton Gillespie, Custodians of the Internet, 251