It's a case of legislation being behind (way behind) current times. Jlocke's ignorance can easily be forgiven, while the Turkish Telecommunications Whatnot Authority's cannot.
Turkish people are quite vocal (online and in the real world) about the ludicrosity of the relevant law. Public pressure on the government on this issue is quite high. I personally deem it good that it gets such a negative coverage here too.
Btw, Google is/has a local company in Turkey (which is in G20), reaping good ad money, selling services, paying taxes. It'd pull out long after it has pulled out of, say, China (which I believe is serious about the filtering thing, unlike Turkish authorities).
The youtube ban is stupid and easily circumvented. This new blockage is a by-product of Google having switched ip addresses or somesuch of said services. It's just a ban that should not have been there in the first place, that's all. The "Kemal Ataturk" law is an old one, and a touchy subject at that. It is difficult to repeal just because of a youtube ban. Thus the ban has been able to last for so long. It's all connected, you see.
Grenade, because it is about politics, not about actual censorship. At least not for youtube, or google translate, or google docs.