Another example is the reddit admins shutting down any subreddit that allows for discussion about digital rights managment. One prime example of this is r/printsf. If you try to discuss how to get your Amazon purchased ebook in a format that can be used with text to speech the local mods of the sub will ban you. This is because if they allow it the reddit admins will ban the sub.
It isn't all direct reddit admin/corporate action. They put the onus on the subs to do their dirty work and enforce the corporate rules to protect their income and interests.