I'm not sure if there are a lot of times where the Internet gets it completely wrong, but there are unquestionably a lot of times where the Internet gets it totally wrong in terms of a proportionate reaction to the original crime. Should someone be getting death-threats for an off-colour joke? Should they lose their job for that sort of thing, or be so affected that they don't want to leave their house? Jon Ronson's writing on the subject (he has a book which I haven't read, but I have seen him talk about it a few times) really captures that element of disproportionate reaction of social media.
http://www.theguardian.com/technolog...one-jon-ronson
One of the anecdotes captures exactly the potential for a shaming cycle (or at least chain reaction) that GP_Matt mentioned. A woman shamed a man for a comment he made, and he lost his job as a result. Then the Internet rallied, shamed the woman, and she lost her job, too.
I don't have a problem with the Internet rallying in a case where law enforcement is doing nothing about an issue, but suggesting that the Internet's ability to punish someone faster than law enforcement is hardly a virtue; figuring out all of the facts and meting out appropriate punishment isn't a process that should be rushed.
Is Palmer suffering a disproportionate overreaction? Hard to say. Poaching is a serious issue that has angered a lot of people for a long time, but it's been hard for us in western society to put a face to the issue. Palmer just made himself the public face of that issue. But the reality is that this sort of shaming isn't going to practically affect poaching in Africa, because most of it doesn't involve western tourists travelling there and hunting with shady permits and practices: it involves locals hunting the animals and then selling them on black markets. These aren't people that you can shame into behaving correctly. The real issue is that animal protection in Africa is chronically underfunded.
So maybe rather than tweeting, people should seriously consider donating to something that is going to help solve the problem. A quick google search turns up this NFP which provides conservation support to the Zimbabwe Parks and Wildlife Management Authority:
http://www.zamsoc.org/?page_id=60
I haven't researched the structure of this organization and I don't advocate donating to NFPs without researching them first. But if everyone who felt it necessary to tweet or yelp-comment about this issue instead (or even additionally) donated, say, $10 toward wildlife conservation in Africa, we'd be far further ahead.