If you go directly to the site you get a message from the Turkish government saying access is not permitted. There are of course many workarounds if you really want to get to it.
I find myself torn on this one and I'm sure 99% of Brits think it is blinkered and has no place in the modern World - but let me try to change your view...
Obviously free speech and access to information is ideal and what everyone should want but the internet brings headaches for all governments, not just the Turkish one. It is illegal to insult Ataturk in Turkey and that is understandable. Insults within the borders would be dealt with, but now insults written from outside Turkey became accessible from inside. It is difficult to know how to deal with that. If anti-British 'clerics' in the UK targeted Churchill as their hate figure, the British government would act to prevent it.
What happened on YouTube was any video about Turkey was a target for anti-Turkish and anti-Ataturk racist taunts. I read quite a few myself. Even in one, about a promising young Turkish footballer of about 13 years of age, I read rants from Greek folk aimed at Ataturk and even the promise to return to reclaim Constantinople. This was a young lad showing some fancy flicks and ball control! In the interests of balance, the return fire was none too pleasant either.
Now, if we allowed people to write things like that on CBF, and the Turkish government decided to block us, I'm sure there would be a lot of sympathy for taking that action, and we would be blamed for allowing it to happen. The truth is, we don't but YouTube did - with all their billions of pounds, the site remained totally unmoderated and that signals that racist attacks in innocent threads are permitted and allowed to stay pretty much forever.
Sadly, ignoring that content is wrong in my opinion. As YouTube ignored all calls to moderate the content of comments on their website, I can't see what else the Turkish government could do to protect it's laws.
