One way to think about this is as a timeline–or a stream. As people share more, the timeline gets filled in more and more with what is happening with everything you’re connected to. The pace of updates accelerates. This creates a continuous stream of information that delivers a deeper understanding for everyone participating in it. As this happens, people will no longer come to Facebook to consume a particular piece or type of content, but to consume and participate in the stream itself.”

A heavyhanded explanation for a simplistic concept, but perhaps there is a deeper meaning to be found in our collective tweet of consciousness mutterings–“John is stuck at SFO,” “Beth is all liquored up,” “Adam is reminiscing about his days on the Newton”…“Mark has a laughably grandiose vision of his social-networking service.”

Or perhaps the deeper meaning here is to be found in another tweak Facebook is making to its service. As part of this redesign, the company is making profiles and pages the same thing. What that means is that pages created by public figures, organizations and companies will now look, feel and behave just like any other profile. Now their proprietors, too, can join “the stream.” “These folks will now be able to share status updates, videos, photos or anything else they want, in the same way your friends can already,” says Zuckerberg. “You’ll be able to keep up with all of their activity in your News Feed. This means that you can find out that Oprah is reading a book backstage before a show, CNN posted a breaking story or U2 is working on a new song, just as you would see that your friend uploaded new photos from her trip to Europe.”

Presumably, that also means folks like Microsoft (MSFT), BlockBuster (BBI) and Coca-Cola (KO) can also tip you off to the fascinating things they’re up to. So in the end, this redesign isn’t about the continuing evolution of the “social graph” or whatever the hell Facebook calls its network these days. It’s about developing a new advertising program that allows businesses legitimate access to the 175 million Facebook members the company has so far failed miserably to monetize.

The ability to control how much information is available to the public has long been one of Facebook’s core principles. It was this very feature, for example, that Facebook used to distinguish itself from other social networks back when it first launched.

Of course, the ensuing years proved that protecting the privacy of its users was not exactly Facebook’s strong suit–especially when it came to digging up the advertising revenues necessary to justify its fantastical $15 billion valuation. There have been privacy issues with Facebook’s news-feed service, with its controversial Beacon advertising system, and with its terms of service, which granted popular applications access to far more personal user data than is necessary.

And now there’s another. A bug in permission restrictions in Facebook Groups allows members to upload content without first receiving permission from a Group admin. I know this firsthand, because over the past few days videos, photos and blog posts have been appearing on the All Things Digital Facebook Group, and neither Walt, Kara nor I–the only three people with admin privileges to the group–put them there (see screen below). Worse, while I was able to delete the photos and blog posts, I was unable to pull the videos off the page. There was no mechanism to remove them.

Worse still, the bug that makes this possible is not specific to the All Things Digital Facebook Group alone. It affects all Facebook Groups, site-wide.

We alerted Facebook to the issue and the company quickly identified the bug. Said spokesperson Brandee Barker: “Engineering has pushed out a fix that should go site wide shortly.”

UPDATE: Facebook engineers fixed the permissions bug, and we were able to remove the rogue videos from our page.

Like the Facebook Platform, “InApps” allows developers to create productivity applications for LinkedIn or to port some of the site’s features to outside Web sites. But unlike Facebook, these widgets must be approved by LinkedIn before they’re deployed.

Clearly, the company has no intention of offering users the chance to send electronic hamburgers to each other, or pop their zits. “What we are trying to do is make professionals more productive by making them able to find one another, learn more about each other and communicate efficiently with each other,” LinkedIn Chief Executive Dan Nye told Reuters. “It’s not a place where you waste two hours of your time trying to find a date.”

Launching in concert with InApps are a new look and a number of new features designed to make the site more interactive. Among them: a news feed customized by the company and the industry in which a user works and an interesting BusinessWeek application that lets you see how you’re connected through LinkedIn to people and companies mentioned in its articles. With such upgrades, LinkedIn–which claims 17 million registered users globally and about 5 million unique per month–hopes to dominate the business of business networking. Personal networking and self-expression, it seems to be saying, are best left to others.

But is it reasonable to think that people will continue to maintain two social-networking profiles–one for their personal life and another for their professional life? LinkedIn CEO Nye says it is, especially given the value proposition LinkedIn offers its users. “…People have profiles on both services,” he told the San Francisco Chronicle. “But on LinkedIn, you’re not going to get poked, there’s no zombies and you’re not going to share your music list. … Now when someone says, ‘Hey, let’s go down and meet at Starbucks,’ you don’t have to ask five people if they’re Tom.”