As more anime come out, I generally see them being censored whether it being violence, sexual, or other things that are deemed "inappropriate". The main reason I've heard is that they withhold that content for people that actually purchase the DVD and/or Bluray of the anime. I personally find that to be extremely sleazy, and make me less inclined to buy any of your content.
The example that seems to be a glaring case of over censorship is Highschool of the Dead. The picture above is a lovely scene in the anime where three-fourths of the screen is black and you can't even see what is going on in the scene at all.
For me, censorship as a whole shouldn't even exist, it is basically a person of power telling you what you can and can't experience. I've been opposed to nearly every kind of censorship that I've seen throughout my life. However, I do understand the stance of self-censorship, even if I disagree with it, there are situation where you can't voice some kind opinion openly.
That being said, anime companies are approaching the selling of their content completely wrong. Instead of remove things from the anime and selling the full product they should be adding additional thing to the purchase. People are far more likely to buy something if they aren't treated like a criminal right off the back when they see things being taken away for no good reason.
As an example, we have regular episodic television where you watch the full content and can buy the product with extra scenes, the shows soundtrack, or maybe even commentary from the cast. It's all about providing an extra amount of content to keep the buyers purchase more lucrative.
Censorship never helped anyone, but the people in power.