Our friends at StormCloudsGathering put together a report on Turkey's YouTube ban, and why it matters to the rest of us. It has to do with Syria, and Turkey's scheme to exploit Syria for its own ends; I recommend that you read the article and--if you can understand the language--watch the video embedded therein.
There are similar reports about this same clique wanting to exploit the Crimea situation, playing into the Twitter ban. These bans are not as effective as it seems, due to widespread dissemination of the IP addresses needed to get around the blocks as well as VPN services growing in size, but Erdogan's core supporters are tech-illiterate true believers and thus easily fall for media propaganda. (Sound familiar? It should.) More of this can be expected everywhere as the system collapses.