whether its 'the devil' or not I would not care to speculate, however I have met a few folks in my day who most clearly and evidently possessed by something outside themselves. I asked my Priest about exorcisms once, he said he was involved in two, one was just an overreacting family to a girl with clear psychological problems, another he didn't care to elaborate on, said it perhaps was the real deal, got rather quiet, looked rather momentarily distraught and immediately changed the subject.
runnin with the devil...
