I recommend that you sit down in front of your computer with your beverage of choice and do a deep dive into psyops.

To address your comment, there are psyops actors in every significant (and some less significant) social media platform, even our own Hacker News. Whether you want to call their work “propaganda” or something else is mostly semantics — they are operating with an agenda, sometimes/often one that conflicts with the will and/or best interest of our nation (in my case, the US).