This is what the guy is complaining about: Facebook and Twitter are still hosting his posts and tweets, but that some of his followers claim not to be getting notifications about every single one of those posts/tweets.

Facebook has auto-throttle: if you post too many times within a span, it stops sending notifications about every post to your followers unless they interact with one or more of your posts during that span. This is desired behavior, by 99% of people, because we don't want our newsfeed flooded by that one annoying friend with no life, unless we choose to follow up.

So no, the EFF and ACLU can't team up on this because there's no active censorship, or even passive censorship.