ADIYAMAN, Turkey — There was little doubt among locals about what went on inside the Islam Tea House, a now-shuttered storefront tucked away on a humble side street in the southeastern Turkish city of Adiyaman. Beyond its windows, once adorned with religious verses in black and white, neighbors say that ISIS sympathizers used to congregate and sometimes press others to join them. “We knew what it was,” said a teenager who works at a nearby shop and was the occasional target of their recruitment efforts. Now everyone knows what it was too — a notorious ISIS recruitment site that for a while operated in plain sight.