In today's world, Internet may have become a necessity, but cyber bullying is far more intense and dangerous than "traditional" harassment because it's harder to escape from the 24-hour online world, a new study has found. 

The research also found that four out of 10 women have suffered electronic harassment after dating online and 20 per cent of online stalkers use social networking sites to stalk their victims.

Lead researcher Elizabeth Carll said: "Increasingly, stalkers use modern technology to monitor and torment their victims, and one in four victims reports some form of cyber- stalking, such as threatening emails or instant messaging."

Victims can feel stress, anxiety, fear and nightmares, as well as enduring eating and sleeping difficulties, the 'Daily Mail' reported. Dr Carll added: "It is my observation that the symptoms related to cyber-stalking and e-harassment may be more intense than in-person harassment, because impact is more devastating due to the 24/7 nature of online communication, inability to escape to a safe place, and global access of the information."

But Dr Carll said the strengths of the internet being exploited by bullies could be turned against them. She said: "The same technologies used to harass can also be used to intervene and prevent harassment. Imagine a cell phone application that can tell you if someone threatening you is nearby. That could be life-saving."