A Russian man named Renad Bakiev was arrested by Turkish police after allegedly plotting to use a drone to attack an American military base, the Associated Press reports.

Bakiev is accused by police of taking steps to procure a drone to be used to attack the Incirlik Air Base, a prominent base used by the United States for missions in Iraq and Syria. Turkish authorities say Bakiev is a suspected Islamic State militant who has traveled to Syria and has attempted an attack on Americans before.

Police were tipped off to Bakiev’s plan after interrogating other terrorism suspects detained in a June counter-terror raid. Police say Bakiev used the social media app Telegram to solicit money for his operation.

Telegram is now a well-known tool for terrorist organizations to communicate, primarily due to its focus on privacy. When looking at the design of the app, it quickly becomes obvious why terrorists would gravitate towards it. Channels can be established within the app that any user can join. From there, invites to private conversations between users can be sent. Once in a private conversation, called a secret chat, encryption keys are exchanged between the users. This is what is known as end-to-end encryption, which means that even the Telegram cannot access the messages being sent between users.