Bottom line is folks on the internet figured out how to take care of trolls like these long ago... deprive them of what they're seeking, which is attention, and they'll go away. Sometimes it's hard to ignore them, and that's where the Patriot Guard Riders come into play. They can ignore the trolls more easily, and can make it easier for the bereaved to ignore them as well.
I agree with Timber - if enough people get off their butts to do something about it, something will happen. I don't encourage the baseball bats, but I certainly do understand them...
Until people do get off their butts, laws will help to alleviate the situation. They won't fix it, but they will help.