Lets talk a bit about privacy vs. support systems.
Over in livejournal, you have the ability to set up filters so that certain posts can only be seen by the people you allow to view that post. Many people, myself included, use this feature to discuss sensitive issues with trusted friends.
A is currently being lambasted by B for having a 'not B' filter. B (who discovered the filter because A forgot to log off) says it's an invasion of their privacy, and is horribly offended that A is taking about their issues to people.
My question is, then, who is A supposed to talk to, and how? It's vitally important for human beings to have a support network that they can go to when they've hit a rocky space. This includes being able to talk about issues you're having with a significant other. Outside perspectives, second opinions, just a shoulder to vent on... all of these things are *nessicary* for the person to be able to go back and work on those issues effectively.
I can see asking for privacy on details, but even then, you need to be able to talk things out. Being angry that your SO has a circle of friends they can communicate with, even if it is through LJ, strikes me as selfish.