Commenting on this particular troll is probably beneath the majority of us.
However, on a general note, I think it is important to realize that every text message you send, every cell phone conversation you have, every post to the CNN forum you make, every tweet you send ... is directly attributable to your IP whether you use your own name or not. With Facebook and Google tracking everything you do, whether you are logged in or not, I would go one step further, and say all of these things are directly attributable to you personally.
I would strongly urge young people to really think about what they are putting out there. Consider this, the military was doing the equivalent of credit checks for sensitive positions during the 60s. Now you need a credit check to do ANYTHING, even things that don't require credit. How long before an internet and phone background check is standard in the background checks organizations do before offering jobs?
I can tell you the military is doing this sort of screening right now for sensitive positions, but at least you are confronted about it. It still basically ends your career, but they will give you a chance to explain your posts. In the private sector in the future, they will just deep six your application and you won't know what happened. Or they'll let you in at entry level, maybe, and subsequently you'll start running up against an invisible barrier as you try to advance beyond the first or second layer of management. Or you will find resistance to you advancing into management at all.
Also be mindful, it can affect more than your professional life. Think about what the background checks for apartments will look like in the 2020s. Or what 'dating sites' will be like in the 2020s.
Please consider your future before you make comments on ... say ... Hurricane Katrina ... that might be misconstrued. Or post an opinion on ... say ... American soldiers in Afghanistan ... that could be taken out of context and viewed in a negative light.
All that said, the absolute best defense against these sorts of situations is just not to be a douche, which isn't very hard. If a guy or girl is dead...leave them in peace. If you can't say something nice...just don't comment.