Only if they are doing REAL damage. Such as if the person they were trolling became suicidal or committed suicide then yes, they should be prosecuted. However if it is classed as cyberbullying then they should as well. However if it is just harmless trolling, then its fine.
Only if you deal the person mental damage and/or if they become suicidal or commit suicide.
You can just shut off, block, or ignore them. If you respond or "feed" them then you deserve what ever happens to you. Trolls are powerless unless you give them power. If you are not stupid then this shouldn't be a very hard thing to do. All you have to do is stop and think.
Trolling is pissing someone off to get a reaction.
The people who do this are no threat to society nor is it a very serious matter.
If someone wants to kill themselves over what someone on the internet said then so be it.
A person choice to kill themselves over something as trivial as trolling should not be taken into account.
I understand there are cases where people are harassed over and over by a person via snail mail ect.
But if someone is leaking ips and home locations ect I am pretty much against that.
But that goes far beyond trolling to an invasion of privacy.