Just got back from Calis and flew Turkish Airlines via Istanbul so I thought I would update you on the procedure. Flying out no problem with my Ipad (the same as all other airlines I suppose) flying back there was a bit of confusion when I looked on the web site it stated that you could take your tablet, lap top or Ipad to the boarding gate and hand that over to the airline staff they would put it in to a plastic bag give you a reference number and that would be put with all the others into a secure box and then put in the hold and given back to you at your destination airport (Uk USA only) but when doing on line check in it stated that all laptops etc. should be put in your hold luggage when dropping of your bags. So when I got to Dalaman I asked at the airline desk there answer was to ask at check in when I got to check in they didn't have a clue so rather than have it confiscated at the gate I put it in my case and hoped for the best.
Going from domestic arrivals to the international departures at Atatürk airport has changed they now filter you out side to come back in through the main doors and through the first lot of security checks and scans when you get through passport control you have another lot of checks, searches and scans and when you get to your gate this has changed to. When you get to your gate the sitting area is all cordoned of and you have to present your passport and boarding card to a member of staff (some of the passports where photographed) then you where ushered to another member of staff who checked your passport again then sent to a row of tables where your carry on bags where searched any alternative battery sources where confiscated and then if you had a laptop or tablet you where then sent to another desk and your item was put into a plastic bag and then into a hard bodied suit case then that was put into the hold (as a note every bag was searched no matter how small).Fortunately when I got back to Manchester my Ipad was still in my bag so worked out ok in the end