Nope, this is not an ISP. Turk Telekom is stated-owned broadband internet (infrastructure) company. All of the ISPs are having the same peering. I checked your link through TTNet. We also have Superonline and Smile as main ISPs.

Turk Telekom is not state-owned, not for the last 8 years or so.

Details courtesy of Wikipedia: Privatized in 2005. "55% of the shares of Turk Telekom belongs to Oger Telekomünikasyon A.Ş. and 30% of the shares belongs to Undersecretariat of Treasure of Turkey. The remaining 15% of shares has been offered to the public." Oger Telekom is apparently 100% privately owned by the Hariri family.

So, still 30% state owned. As one point of reference, the German government still holds 15% directly plus 17% indirectly of Deutsche Telekom. France and Orange (nee France Telecom) are similar.