Today we find ourselves dependent on cellphones, computers and electronic diaries and we wonder how we managed without them. The more dependency and the utility of them in day to day work have given birth to the darker side of internet age. Network crimes are the most unpredictable calamity on the cyber world. Unauthorized access, hacking, spreading of viruses, smashing computer networks on very large scale, the brutal weapons like e-mail bombing, logic bombs resulting into the disrupt behavior of computer networks are very few incidences of recent days. This crime is high-tech and needs trained and equipped personnel to man investigatory and prosecuting agencies for effective prevention and control of computer related crime. Due to this we can't avoid using internet or online transaction, we must have some knowledge about data security. so update yourself with information. Maybe we can't stop it but chances to avoid is possible.