Just differences of opinions, why a death sentence?

I have an observation on human behaviour, society, anger and the bandwagon? I want to understand why some people behave the way they do and none of my keywords connect to any helpful articles/research on the internet. I am a 16 year old female and I'm surrounded by a messed up teenage society. I am a huge social networker, Twitter in particular and I have realised that when a heated row arises in a fashion where pretty much the whole of my teenage generation gangs up on 1 person for something they have done wrong takes place. Now, I don't disagree with this individual being publicly recognised for his disgusting, abusive behaviour (which is another thing about how people behave, why would this person say such horrible things? how can he even type the things he does and not feel guilty??) but what I do disagree with is everybody joining the bandwagon of hating on this individual. There are even people taking it to the extremes by encouraging suicide and wishing death/pain on them. It made me feel like I want to stick up for this attacked individual but in actual fact he gets what he deserves, but not this bad.. Afterall how many of us are without sin, yet you'll find every Tom, Dick, Harry and Jane clamouring to conderm and cast the first stone. I'm sitting on the fence between these 2 sides. How can a person wish that upon somebody? I would NEVER even dream of wishing pain/death upon my worst enemy. Has it got something to do with ethics and how a person expresses and responds to their own anger? And what does it say about compassion, tolerance, understanding and forgiveness? Why haven't we, in this age and time outgrown the Lynch mob mentality? I don't know, I would really like to look into human behaviour and how their minds work. I have considered the factors that people on Twitter say things to receive publicity and popularity. But I thought there was an extent that humanity will go to,but now I'm not too sure. I have also considered that we are teenagers and we are naive/immature. But I contradict this, evidently..? I tried to talk about it to my friend but he doesn't understand, nobody is in the same boat as me, they're all on 1 side and he thinks I am crazy for even considering sitting on the fence when this individual has said some really inhumane, but clearly ill-thought, stupid and ridiculous things. I just think sometimes we should be less judgemental and conderming and realise we too could be that 1 person, one day. That's just my view anyway.