Catholic Exchange is a great wealth of articles and support for the faith. They are running an article on Bartolo Longo which is well worth the read.
Among the wayward students in Naples, one stood above the rest in the depths of his depravity. As a young man, Bartolo not only participated in the anti-Catholic demonstrations, he not only preached publically and vehemently against the faith, he not only sought psychic mediums with his friends — he went even further and became a Satanic priest. Later on, Bartolo would describe how, in the rites of his blasphemous "ordination", he promised his soul to a spirit-guide, a demon, which shook the walls and manifested itself with blasphemous shrieks.