With the advent of the social internet, people are sharing all sorts of things they never thought they would. This is information that, as recently as the late 90's (or even later), would have been considered private. It wouldn't have been considered private because it was particularly personal - it was just stored locally, and always had been, so it was automatically private. Bookmarks would be a prime example.
Web 2.0 changed all this. Sites like del.icio.us made it possible for anyone to share their bookmarks with the world. Something that was always considered private, was now public. And it was ok. This had all sorts of nice benefits, like letting people collaboratively sort through the internet, and share the good parts, quickly and easily. More and more things are going public, and for the most part, it's great.
The question is, how far will this trend go? How much are people willing to share? As more social tools mash up other social tools, active users of these sites are starting to have a real identity on the internet. It may not be exactly the same identity they have in real life, but it is still one cohesive presence for all of their activity on the internet. Actions and statements are starting to have consequence. They stick to the identity of their owner.
It's starting to seem a lot like... real life.
The term publish generally implies a high degree of selectivity. Or at least, it used to. Now, with people sharing so much information so freely, publication has moved towards becoming the default that privacy previously was. It's not there yet, but it's certainly gotten closer. I can't help but wonder, where will the balance between public and private information be struck? And when it finally is struck, if the Web 2.0 boom hasn't drowned itself in buzzwords by then, will this finally be the wall it hits?