Celebrities, such as Bieber, knowingly expose themselves to public critique when they share things about their personal lives in appearances or on social media. That's part of being a public figure, whether you like it or not. But well-informed critique is not the same as abuse and bullying; the latter is written with the explicit intent to hurt the person the comment is about.It's not (necessarily) that trolls are terrible people. When we post in comments sections, it can feel like a safe forum in which to vent. It can even be a power trip. Here are celebrities making millions of dollars, and yet anyone can "speak" to them through their social media account. You can touch their lives in some way, if only for a fleeting, @-reply moment.And perhaps there's a disconnect. We know that teenagers bullying one another online is bad, but we don't recognize that we're behaving that same way in our comments to celebrities.As The New Yorker has noted, a large group forum (such as a comments section on a post) can create a psychological effect known as diffusion of responsibility. Someone who types something mean will feel less accountable if others are also writing negative comments — and so it snowballs into an unbearable situation like Bieber's.Furthermore, research has found that those who comment anonymously are even more likely to feel unaccountable online. This means that those who hide behind the safe cover of an ambiguous account can post freely, without feeling any responsibility for their words. (However, other studies have found people can be just as mean without pseudonyms . We're just as comfortable hiding behind our phone screens as behind fake names.)Online bullying is no less hurtful than comments spewed hatefully in person, and psychologists have said it's unhealthy — not just for the recipient, but for the writer of the vitriol, too.Typing hurtful, negative comments is a waste your own time and energy and everyone else's. If we want to change the largely hateful culture of online discourse, we, as fans and followers, need to take responsibility and start looking at our own behavior with a more critical eye.