"Founder of Hasidism," is a book by Moshe Rosman about the Baal Shem Tov. In it he describes the genesis of the term "ba'al shem." According to Rosman, "ba'al shem", literally, a"master of the name," referred to an individual who knew how to use God's Name to pull stunts like moving souls around, disappearing, and shortening distances between places. During the middle ages, there were many "ba'alei shem" and their ranks included such luminaries as R' Yonasan Eibeshutz. R' Yonasan Eibeshutz in particular described the wonders he performed in his writings.
I am somewhat skeptical that the people can work magic by using God's Name or other kabalistic incantations, but I suppose I can't rule it out. What bothers me is if I don't believe these stories, that basically means I am calling the Baal Shem Tov and R' Yonasan Eibeshutz either charlatans or delusional. No?