The web was initially designed by Tim Berners-Lee to provide open exchange of information and ideas. When one group of people can control access to that exchange based on their own bias it becomes censorship.
That's just what the US Government has done with regards to Cuba. What's worse is that the sites it has blocked are European ones, where no embargo on Cuba exists.
The article mentions the fact that the US controls the top-level domain naming system (something I've posted about before). I think it's time for the UN to step in.