Wow. This is absolutely fascinating. With this campaign, Greenpeace has shown more Internet savvy than the vast majority of professional "viral" marketers.

I'm not going to weigh in on the moral aspects of this incident, as I don't particularly care. I'm far more interested in the mechanics of how this was pulled off, as it has huge implications for corporations, activists, and even political candidates. I could easily see some Obama supporter pulling something similar and creating a firestorm around the Romney campaign.

Love it or hate it, these tactics are here to stay. It will be incumbent upon entities with interests in online perceptions to guard themselves against these kinds of attacks and, should the pros outweigh the cons, engage in them as well.