When you’re being physically attacked, you can call on a variety of organizations to defend you — the police, the military, whoever does antiterrorism security in your country, your lawyers. The legal structure justifying that defense depends on knowing two things: who’s attacking you, and why. Unfortunately, when you’re being attacked in cyberspace, the two things you often don’t know are who’s attacking you, and why.
Whose job was it to defend Sony? Was it the US military’s, because it believed the attack to have come from North Korea? Was it the FBI, because this wasn’t an act of war? Was it Sony’s own problem, because it’s a private company? What about during those first weeks, when no one knew who the attacker was? These are just a few of the policy questions that we don’t have good answers for.
–Bruce Schneier on attack attribution.
Schneier is talking geopolitics here, but this could just as easily be applied to online harassment. Laws and institutions just aren’t keeping up with the technology.