Medioimages/Photodisc via Slate  
Psychologists who study internet trolls have bad, though possibly unsurprising, news for us: Trolls are not nice-but-troubled people. According to a recent article by Chris Mooney in Slate, they

Really Are Horrible People

Narcissistic, Machiavellian, psychopathic, and sadistic.
This assessment is based on a study from the University of Manitoba which concludes,

Of all personality measures, sadism showed the most robust associations with trolling and, importantly, the relationship was specific to trolling behavior. Enjoyment of other online activities, such as chatting and debating, was unrelated to sadism. Thus cyber-trolling appears to be an Internet manifestation of everyday sadism.
But there’s a risk in making trolls more important than we need to. As Sandra Todorov puts it, responding at Spiked Online to calls for more censorship,

If you don’t like people saying mean things to you online, if it hurts your feelings, there’s something very simple you can do: stay off it. Millions of people do this every day, without fanfare. Maybe they can’t deal with criticism. Maybe they can’t deal with the occasional idiot calling them fat or stupid. Maybe they simply do not enjoy the experience. These people could be accused of being a bit oversensitive, but compared to Dunham they are heroic freedom fighters – at least they don’t want to censor others.
Noting writer and actress Lena Dunham’s demand for more censorship of Twitter, she replies,

Twitter is already a hostile place for free speech, where voicing certain opinions can get you twitch-hunted – or even cost you your job. Dunham’s call to regulate Twitter further is not about protecting free speech, it’s about increasing the power of the twitch-hunters.
Indeed, when I heard the name “Lena Dunham,” I rushed to the files, and sure enough, I would not want her on my side in a case against any legitimate abuse. One of her own claims seems to have fallen apart under scrutiny.
Well, the best offense is a good defense so, staking a middle ground, here are some useful tips for controlling trolls: From Webroots:

If you’ve spent any time online, you’ve probably run across trolls even if you didn’t know the term. You may have tried to reason with them, be nice to them or virtually shout back at them. Don’t bother. You’re more likely to win an argument with a tree than you are with a troll.
Calling them out in front of others and then ignoring (possibly removing or reporting) them is recommended. From Make Use Of:

There are different types of trolls. Most are hit-and-miss and are far easier to deal with. Some are more strategic in the way they embed themselves online so as to cause maximum mayhem with minimum fuss. Identifying an internet troll is half the battle one. You can only count on your experience to get one early before you are baited by them.
And lastly, from an advice site for police department social media

Most — if not all — social media managers have a slew of curse words placed into the profanity filter of our Facebook pages. This will cause a post to automatically be hidden to everyone except the person who posted if it contains any of those words. Note: If even the police have problems with social media trolls, we should feel better about the extent we succeed in controlling them ourselves.
As one reformed troll puts it:

If you don’t have principles on how to deal with trolls, now is the time. The reason why abiding to principles is so helpful is because they tell us how to act. “Do this, not this.” It focuses on the long-term outcome, whereas acting on our impulses creates many possible—and unfavorable—results. If there is one thing I learned both in psychology and philosophy, it’s this: No one can hurt you. It is what we tell ourselves about the specific event or person that creates the feeling. So if we’re telling ourselves, “How dare this person say this to me,” we’re creating feelings of entitlement and anger. In the words of Marcus Aurelius, “It can ruin your life only if it ruins your character. Otherwise it cannot harm you — inside or out.” See also: If the Internet is a well-travelled sea, then Internet trolls are its brigands Trolls can potentially destroy reputations and careers other than their own.
From the vid below, cheer up: “When they write, it’s a blog. When you respond, it’s a press conference”:
 

Denyse O’Leary is a Canadian journalist, author, and blogger.