A warning to any US citizens headed to Turkey in the near future...
http://www.bbc.com/news/world-europe-41547502
Turkey and the US have both stopped issuing visas to each others citizens. This includes e-visas and visa-on-arrivals that US citizens usually require to enter the country, which basically means that US citizens can no longer enter Turkey unless they have an existing, unexpired (e-)visa!
Given no visa is required for international transit (on the same ticket, at least) anyone simply connecting on TK in IST should be fine, but otherwise...
This also impacts Turkish citizens, but with a little less impact as viasa are required in advance so it's not a matter of finding out on arrival at the airport.
Depending on how long this lasts it'll be interesting to see what impact it has on TK's operations, and how long until we start seeing flights canceled as a result.