As it passed another major milestone, social networking giant Facebook is moving once again to overhaul its privacy policies in a bid to give users greater control and understanding about how their information is shared.

In a blog post late Tuesday night, Facebook co-founder and CEO Mark Zuckerberg said the company is abandoning its regional networks, the groupings of users devised by where they live, that had guided the company's approach to privacy.

Under the previous model, a user's information was shared by default with other members of his network, be it a school, club, city, or even a country.

Zuckerberg said that in the next two weeks, Facebook will phase out the network approach and prompt users to review their privacy settings.

The reason given? Facebook's growth continues unabated, making the regional networks too unwieldy to guide its privacy model for individual users, Zuckerberg said, taking the occasion to note that Facebook has now signed up more than 350 million users.

"This worked well when Facebook was mostly used by students, since it made sense that a student might want to share content with their fellow students," Zuckerberg said. "However, as Facebook has grown, some of these regional networks now have millions of members and we've concluded that this is no longer the best way for you to control your privacy."

With the networks on their way out, users will receive a message explaining the changes and directing them to a page to update their settings. Under the new model, Facebook is consolidating some of its controls in an effort to simplify its privacy apparatus.

It is also extending users the granular control over which members of their network see individual pieces of content as they are uploaded.

"The plan we've come up with is to remove regional networks completely and create a simpler model for privacy control where you can set content to be available to only your friends, friends of your friends, or everyone," Zuckerberg said.

Facebook's latest round of changes follows what's been a busy year on the privacy front for the company. Just two weeks ago, Facebook enacted a new privacy policy, a document that came in response to complaints from both its users and government regulators.

In August, Facebook reached an agreement with Canada's privacy commissioner to update its privacy guidelines, with a particular focus on making users better understand how their information was being shared, collected, and stored.

Canada's long-running inquiry overlapped with a controversy Facebook invited earlier this year when it changed its usage agreement in such a way that appeared to assert perpetual ownership over users' data, even after they had deleted their accounts.

Facebook quickly backpedaled, and announced a new model of governance that would invite comment from the site's users on major policy changes, such as the recent update to the privacy policy.

Facebook is also looking with a wary eye toward Capitol Hill, where lawmakers have been working to draft legislation that could set sweeping new rules for how Internet companies treat their users' information.

Kenneth Corbin is an associate editor at InternetNews.com.