In this work of felt need round the globe the experienced author has discussed the intricate problems that are being faced by the international community every moment and also their probable solutions. With advancement of technology the cyber criminals very often trespass, destroy or alter computer, computer system, computer programme, software, network and related devices. While dealing with this emerging subject the author has taken adequate care to incorporate the issues like classification, nature and elements of cyber crime, activities of the cyber hackers, cyber frauds, cyber pornography, online child pornography, cyber terrorism and so on.