I deleted my posts/comment history, resigned as a mod, and logged out for good. The best protest you can do is leave at this point. Anything short of private, restricted, or NSFW-abuse only serves to drive traffic for them and allows them to continue to serve ads.
The John Oliver idea was clever but should have stopped after he responded. It is now only driving traffic to the site and giving them classic “haha isn’t the internet funny?” free marketing on news outlets. They’ve even explicitly said in interviews they don’t mind it at all. That’s not a protest. No one is upset to see John Oliver memes on one sub and be in on the joke.