Getting back to the conversation a few months ago about why John Doe suits based on IP addresses should not be legally recognized:
There's also the extortion issue. In cases where porn publishers threaten to sue alleged infringers, merely the act of naming someone as a defendant in such a case can cause irreparable harm to his reputation, even if he's ultimately found innocent. Even if you win, you still lose, and John Does would in many cases rather settle than be named publicly.
In cases where a person's reputation is at stake, burden of proof MUST be stronger than an IP.
Guess who one of the guys being sued for downloading porn is?
A blind man.So yeah, IP addresses aren't really a very good form of evidence.
(OTOH, a guy who can't secure his own damn router should probably not be working in network security.)