Having been a victim of such harassment in the past myself I agree wholeheartedly, I reported it to the police however they fairly resoundingly didn't appear to give a toss.
Given how common it is for one's name to be googled by others these days online harassment can be every bit as damaging as real life harassment, it caused me quite serious upset for some months. This wasn't merely some childish dispute but an ex looking for revenge over every medium possible, creating profiles on facebook, bebo, myspace and various other websites with the specific intent of causing me as much damage as possible.
While I'm in no means in favour of putting the internet under any form of state control this sort of activity warrants police attention and needs to be against the law. It strikes me as insane that so much focus is put on policing the internet to stop file sharers as opposed to protecting the individual.