Here are a few quotes from Time:
"If they are true, it suggests there are two parallel universes in Turkey," says Hakan Altinay, director of the Open Society Institute, a think tank. "There are people who wake up every morning and plan murders of political opponents, plot coups and how to destabilize the country," he said.
Most Turks have long suspected the existence of a covert web of elements within the security forces and bureaucracy who act outside the law to uphold their own political ends. There is even a household name for it: the "deep state," referring to a state within the state.
Newspapers have suggested that this network is the Turkish remnant of Gladio, a Cold War-era program, orchestrated by the U.S. in several NATO countries, to create a covert paramilitary force to counter Communist activities.
...the audacity and sheer scope of the allegations raises the unsettling question of whether the individuals arrested might just be the tip of the iceberg. "Who gave the orders? Who protected them for this long?" says Altinay. "We are faced with the possibility that this network existed. And, even worse, that it might still exist."