Citizen's law enforcement on the High Seas

For whatever reason, I find it fascinating to study the different ways courts handle legal standing for public interest cases. Many countries reduce the procedural requirements for citizens bringing lawsuits in public interest or citizen's suits. I'm currently working on two papers on environmental citizen's suits (Pakistan and the E.U.). However, I did think it worth raising one interesting question.

As some of you might be aware, the conservation group Sea Shepherd has made it its business to harass Japanese whalers in the Antarctic Sea. They allege that Japan's whaling ships are violating both the International Convention for the Regulation of Whaling and Australian law. I think they have some good law on their side, although then again I'm biased - I had up close encounters with Humpback Whales in Antarctica. For more background, check out the book Harpoon.

Recently, the BBC reported that the Sea Shepherd's efforts have reduced Japan's whale harvest by over half. This is certainly a victory for the whales. However, it also raises interesting legal questions. Most governments allow citizens to enforce the law as "deputy sheriffs," but within the confines of courts and traditional litigation. In the whaling case, activists did seek and obtain a court judgment against the whalers, but to no avail. As such, when is it appropriate for citizens to use other means to enforce the law when governments can't or won't? Where is the boundary between neighborhood watch programs and vigilanteism? 

I certainly sympathize with Sea Shepherd's dilemma and appreciate that some environmentalists are really making sacrifices to protect wildlife (as opposed to just writing yet more policy reports). With the rise of the internet and individual agency, it is now easier and cheaper for citizens to organize and punish violations of law. I think we'll be seeing more of this type of "citizen's enforcement," at least where courts and the rule of law remain weak (like some countries in Southeast Asia).