[mrtksn]

Correct. However, I believe it's not because the government mandated it. The same website could be blocked differently on different ISPs. For example, when Wikipedia was blocked it was not possible to access it without a VPN from Kablonet but a simple DNS provider change was enough on TurkNET.

[anticensor]

Turkcell implements the most powerful censorship and Turk Telecom has the most sophisticated censorship infrastructure in Turkey.

[mrtksn]

what's the difference between powerful and sophisticated censorship mechanisms?

[anticensor]

The sophisticated one is distributed and also more resilient against workarounds, the powerful one is centralised yet has the ability to process most requests per unit time without visible degradation on connection speed and latency.