IMHO, this was an approbate response. There are borders which are not to be crossed. This guy crossed one of them and got what he deserved.
Too much freedom (including, but not limited to freedom of speech) very frequently leads to people abusing it. This usually ends badly (too much democracy can even lead to a downfall of the whole country). Sometimes, people need to be reminded that they can do as they want, but only as long as this doesn't harm other people around them. If they hurt other people, they deserve punishment, which needs to be harsh, otherwise it'd be ineffective. As long as there's a balance between freedom and control, it's fine. Also, the dumber people are, the control has to be stricter. Ideally, the more intelligent one is, the more freedom he would have. Unfortunately, this would never work in real world (though IMHO, it'd be a quick patch to utopia if it did). For me, trolling is the height of stupidity (being completely pointless and serving only to hurt people), and thus, trolls should have their freedom limited.