It's much easier to vent about traumatic events anonymously online than it is in real life. You often get a good reflection of someone's emotional and psychological stability by what they post online on anonymous social media like tumblr and public forums.
Sure, some of them can be pretending, most just want attention, but it's not really right to trivialize their problems, no matter how insignificant you believe they are. Some people have literally nowhere else to go.