So how to they catch all those "online pirates"? I am sure they don't provide their address, name, and social security number when they download a song for example. However that has not stopped thousands upon thousands of cases to be filed (now whether you think identifying people by IP is right or wrong is besides that point, it is happening and it is part of the system). So "no" you should not leak anything to these people unless you know every well how to hide (chances are you might not, even your browser's identifying info like fonts, OS version etc. can be used to narrow down the search and there are other things as well).
If you're going to be that paranoid, you should consider carefully the credibility of whoever you're leaking things to. Do they have a track record of keeping secrets? How hard are they for The Man to pressure? And so on. Wikileaks does very well by those criteria. The WSJ has less of a track record, and inspires less confidence with their privacy policy and somewhat dubious web site security.
The best thing that could happen is that the WSJ hears criticisms like this, takes them to heart, and turns into a serious competitor to Wikileaks. As it is, though, they've got a lot of catching up to do.
So how to they catch all those "online pirates"? I am sure they don't provide their address, name, and social security number when they download a song for example. However that has not stopped thousands upon thousands of cases to be filed (now whether you think identifying people by IP is right or wrong is besides that point, it is happening and it is part of the system). So "no" you should not leak anything to these people unless you know every well how to hide (chances are you might not, even your browser's identifying info like fonts, OS version etc. can be used to narrow down the search and there are other things as well).