Assuming you mean Internet Troll:
AN INTERNET TROLL:
In Internet Terminology a troll is someone who comes into an established community such as an ooline discussion forum and posts inflammatory, rude, repetitive or offensive messages designed intentionally to annoy or antagonize the existing members or disrupt the flow of discussion, including the personal attack of calling others trolls. Often, trolls assume multiple aliases, or sock puppetts.
An Internet "troll" is a person who delights in sowing discord on the Internet. He (and it is usually he) tries to start arguments and upset people.
Trolls see Internet communications services as convenient venues for their bizarre game. For some reason, they don't "get" that they are hurting real people. To them, other Internet users are not quite human but are a kind of digital abstraction. As a result, they feel no sorrow whatsoever for the pain they inflict. Indeed, the greater the suffering they cause, the greater their 'achievement' (as they see it). At the moment, the relative anonymity of the net allows trolls to flourish.
Trolls are utterly impervious to criticism (constructive or otherwise). You cannot negotiate with them; you cannot cause them to feel shame or compassion; you cannot reason with them. They cannot be made to feel remorse. For some reason, trolls do not feel they are bound by the rules of courtesy or social responsibility.
Perhaps this sounds inconceivable. You may think, "Surely there is something I can write that will change them." But a true troll can not be changed by mere words.
FOR MORE INFO SEE: http://hometown.aol.com/intwg/trolls.htm
Why Do They Do It?
Regular net users know how delightful it is when somebody responds to something they have written. It is a meeting of the minds, which is an intellectual thrill, but it is also an acknowledgement of one's value - and that can be a very satisfying emotional reward.
Trolls crave attention, and they care not whether it is positive or negative. They see the Internet as a mirror into which they can gaze in narcissistic rapture.
If you want a deeper analysis than that, perhaps a psychologist can shed some additional light on the matter.
The term "troll" can mean a number of different things, but in essence, a troll is a person who aims to have 'pleasure' at your expense. There are two main types of trolls:
people who have the psychological need to feel good by making others feel bad.
This is a sort of "psycho troll", whose deception involves deceiving themselves as well as others. Such people may use their real names on the internet, and they may not even realise that they are "trolling" because it is all subconscious.
people who pretend to be someone that they are not - they create personae that you think are real, but they know is fictitious.
There are four types of these trolls:
Playtime Trolls: an individual plays a simple, short game. Such trolls are relatively easy to spot because their attack or provocation is fairly blatant, and the persona is fairly two-dimensional.
Tactical Trolls: This is where the troller takes the game more seriously, creates a credible persona to gain confidence of others, and provokes strife in a subtle and invidious way.
Strategic Trolls: A very serious form of game, involving the production of an overall strategy that can take months or years to develop. It can also involve a number of people acting together in order to invade a list.
Domination Trolls: This is where the trollers' strategy extends to the creation and running of apparently bona-fide mailing lists.
Dealing with Trolls
Here are some ideas to help avoid being deceived by trolls:
Before you invest your trust in someone - either emotional or financial trust - you should verify their bona fide nature from multiple known, reliable and independent sources.
ignore postings that you think are suspicious.
beware of off-list emails that praise and flatter, or seem to evoke sympathy. If you feel yourself beginning to like someone, ask first: how much do I know about them from real life sources?
if you do get involved with anyone via the internet, seek out verifiable data. Real people will provide information about themselves that is open-ended and leads to a myriad of sources which enable you to verify their genuine status.
if you are concerned by email list/group postings, write to the listmaster about it.
listmasters can also make their lists restricted, and conduct a security analysis of each list application before allowing them to subscribe. This is probably easier to do in areas that have professional associations or qualifications.
"You can't have a picnic without ants."
The only way to deal with trolls is to limit your reaction to reminding others not to respond to trolls
This will defeat their ego trip and they will fade away.