The gist is that ESN, the global Event Subscription/Notification system for LiveJournal that's been an idea for much of the site's life, has gone live in its initial form, enabling users to subscribe to notifications of new comments on a particular thread or post, and receive notifications of all kinds of things, such as when a user friends you, or when a user uploads a new userpic. The only problem with the timing of the public launch of this system was that it coincided with the launch of a similar system by "rival" networking site Facebook.
Going back to the news announcement, this led to ignorant users commenting with lines such as "first Facebook, now LiveJournal". Worse, because Facebook screwed up its implementation so royally that it was forced to add privacy controls after a backlash from its userbase, even more ignorant LiveJournal users predicted a doom filled with stalkers using LiveJournal's ESN system to harrass people.
Now, it's not these users' job to know the history of the ESN idea and on-again, off-again implementation over the years, and that the public launch just happened to occur in the same week of another site's launch, but that doesn't excuse the numerous assumptions and so-called "predictions" made out of sheer ignorance. While not impossible, it's really quite tricky to see one site announce a feature, then within a week program, test and roll out a similar feature on a mass scale that's more robust and respects people's privacy.
In all honesty, it requires all of my willpower not to leave multiple "STFU" comments in news every time the grunts show up. For a more detailed breakdown of the "privacy trainwreck" that plagued Facebook this week, you'd have fun reading this paper.