The first thing to remember is that NO ONE has a right to harass, threaten and disturb you. Often, victims feel that somehow it is their fault that they are being stalked and that they do not deserve professional help. Once you are aware that you are being harassed, then the harasser has stepped into the crime zone and legal action should certainly be taken. There are a number of steps that can be taken in addition to merely informing the police.
Trying to retrace your steps to work out what you have "done" to deserve this treatment will get you nowhere. The attack or harassment is usually motiveless and you will definitely have difficulty understanding the psychology of the harasser and why he or she is after you, specially if he or she suffers from a psychiatric illness. With some kinds of online harassment it is better not to waste time trying to work out "why" and to concentrate rather on what you should do to get rid of the problem now that it exists.
Learn about Cyberstalking
Avoiding stalkers
Monitoring children
Children and teenagers must notify their parents immediately. Too often, youngsters feel that they will get into trouble with their parents if they know that they have had contact with a stranger. They are usually unaware of how much more trouble they will get into by maintaining such a relationship. There is nothing wrong with having contacts online and making new friends. But the very moment one feels that the online behaviour and language of one’s online contact makes one feel uneasy, one should trust one’s instinct and break off the relationship before it goes out of hand.
Adults should communicate with their immediate families and be prepared for an uphill legal battle as, unfortunately, many states do not have cyberstalking laws in effect yet. One must file a written complaint to the Commissioner of Police in one’s city as soon as possible. In November 2000, The Mumbai police helped rescue a 16-year-old boy who was kidnapped by a female paedophile. She had befriended him through a chat room.
You should also report harassment mails to your Internet Service Provider (like VSNL etc) & your e mail provider (like hotmail, yahoo etc) and take advice from technical savvy peers. Even the creator of the rampaging “I love you” virus was tracked down by street-smart users. A stalker does leave behind a distinct electronic trail through his I.P. address and, though it is not easy, it is possible to trace the stalker to his place of residence.
Though the victim may be loath to do so, keeping thorough records of every single stalking incident that one has had will be a tremendous asset to the police. It certainly requires a lot of presence of mind to be able to look beyond the immediate threat of a stalker and to keep a cool head at all times. The behaviour, choice of language, and temperament of the stalker will make it much easier for the police to build a profile and narrow down the range of suspects. All online conversations with a stalker should be saved as word documents or otherwise for later reference by the police. Of course, if the stalker also operates in the real world, other details like handwriting, license plate numbers, dress, time of day, and if available, return numbers from caller ID units all help to guide the police to the stalker's door.
Refraining from communication with a stalker is not an easy task though it may seem so to one who has not experienced being stalked. It is especially hard to stop oneself from responding to a stalker if he or she happens to have had a close relationship with the victim in the past - that is, before things got ugly. However, contact should be avoided at all costs regardless of any previous relationship with the stalker. By attempting to initiate contact, even for a good purpose, the victim may be unwittingly reinforcing and aggravating the behaviour of the stalker. Even trying to reason with the stalker may make him or her feel under threat or, worse, feel even more in control. This is especially true for stalkers with psychiatric illnesses and their volatile temperaments can be offset far too easily.
Reference
How to Handle a Stalker
http://www.psych.org/pnews/99-12-03/howto.htm
Dealing with stalkers
http://www.thesite.org/homelawandmoney/law/victims/dealingwithstalkers
Cyberstalking
http://www.ccmostwanted.com/topics/cstalk.htm