Do the Orthodox pray to John the Baptist? If not, why not? Do they have any special reasons for not praying to him?
John the Baptist or John the Forerunner is a revered Saint: he is considered the last of the Old Testament saints that went before Christ. There are numerous examples of iconography Saint John the Baptist icon and even Orthodox churches with John as their patron saint e.g. St John the Baptist Church, a parish of the Russian Orthodox Church in Canberra, Australia, as well as six separate feast days. More information here: Orthodox Wiki: John the Forerunner
This should be obvious, given St. John's prominence in the Bible and the life of Jesus, and indeed a simple google search turns up many, many Orthodox Prayer formulas from a variety of Traditions.