In the tiny town of Pliska, a former capital of Bulgaria set amid rolling plains, a mother and son are hard at work, posting pro-Russian propaganda on Facebook from the projection room of a disused outdoor movie theater.

Within a day, according to Bulgarian media, they publish hundreds of screeds against refugees, Turks and Roma, and pieces full of praise for Russian President Vladimir Putin and the leadership of the largely pro-Kremlin Bulgarian Socialist Party. But while their posts follow Moscow’s line, like so many other trolls here, the roots and motivation for their operation appear entirely Bulgarian.

For outside observers trying to grasp how pro-Russian disinformation could impact Bulgaria, a member of both the EU and NATO, therein lies the catch.

“It’s not about Russian propaganda in Bulgaria,” sociologist Bojan Znepolski commented in April to the daily Dnevnik (Journal), “but rather pro-Russian Bulgarian propaganda.”