Amid rising concerns that the world's biggest social network is putting its users' privacy at risk, Facebook has confirmed that it is holding an all-hands company meeting this afternoon to discuss the issue.

"We have an open culture and it should come as no surprise that we're providing a forum for employees to ask questions on a topic that has received a lot of outside interest," Facebook spokesman Andrew Noyes told InternetNews.com in an e-mail.

Noyes declined to comment on what, if any, policy changes might come out of the meeting.

The news of the meeting was first reported in an unconfirmed post on the All Facebook blog, which speculated that the company could shift its controversial new Instant Personalization feature to an opt-out model, or shut it down altogether.

That feature, which automatically shares users' information with selected third-party sites, has drawn sharp criticism from users, privacy advocates and government officials.

But it is hardly the only one.

Facebook has implemented several changes to the settings that govern how and with whom users' information is shared that critics see as chipping away at privacy on the site.

A new feature called community pages, for instance, automatically funnels certain profile information such as a user's home town or college to the topic pages set up for those cities and institutions. Community pages don't offer users the chance to opt out of sharing their information.

On Tuesday, European data-collection authorities organized under the Article 29 Working Party sent a letter to Facebook calling recent changes to the settings on the site that made profile information available to everyone by default "unacceptable."

The group called on Facebook to allow users to create profiles and log in under pseudonyms, and suggested that sharing personal information with Facebook's business and advertising partners without obtaining "free and unambiguous consent" would run afoul of European privacy laws.

Facebook officials said that the company is reviewing the letter and that the company agrees with many of the points the officials made, but that it is unwilling to entertain the suggestion of allowing the use of pseudonyms to protect users' privacy.

"Facebook has always been based on a real name culture, and we fundamentally believe this leads to greater accountability and a safer and more trusted environment for our users," the company said in a statement. "There are plenty of places on the Internet where a person can be anonymous—Facebook is not one of them."

The company also defended its approach to privacy, arguing that the numerous tweaks it has made to the profile settings have equipped users with an unparalleled set of granular tools to fine tune who can see what information about them on the site and around the Web.

Critics counter that that's just the problem, that the cumulative effect of all those changes has been to establish a labyrinthine maze of privacy settings that few users will be savvy enough to navigate, and even fewer will take the time to do so.

Others argue that Facebook's site changes, particularly setting sharing defaults to "everyone" and making some information publicly available with no opt out, fit into a troubling pattern of harvesting ever more data from its users to further its commercial goals while paying lip service to meaningful consent.

The Electronic Frontier Foundation, for instance, has plucked some of the more brazen changes from iterations on the privacy settings over the years to compile a timeline it calls "Facebook's Eroding Privacy Policy."

Calls for a boycott of the site have begun to sprout up around the Web. Of course, that keeps with a well-documented pattern that has seen the company introduce new features or policy changes only to spark the outrage of a small, but vocal, subset of users, occasionally attracting the attention of government officials or provoking a lawsuit.

In some cases Facebook has backed down and apologized. In others, it has added minor modifications or simply let the storm blow over.

But this time could be different.

Facebook has acknowledged that it is running into an image problem, reflected both in today's all-hands meeting and in the recent appearance of Public Policy Vice President Elliot Schrage on the New York Times Bits blog, where he answered pre-submitted questions from readers on a variety of issues, and offered a bit of a mea culpa.

"It's clear that despite our efforts, we are not doing a good enough job communicating the changes that we're making," Schrage wrote. "Even worse, our extensive efforts to provide users greater control over what and how they share appear to be too confusing for some of our more than 400 million users."

Schrage promised that Facebook would soon offer clearer guidance on navigating the privacy controls and work to simplify their settings.

In the meantime, Facebook officials recently met to discuss the privacy issue with the staff of Sen. Chuck Schumer (D-N.Y.), who along with three other senators had sent a letter asking the company to reverse the privacy changes it enacted last month that send information to third-party sites unless users change their settings to opt out.

Schumer also called on the Federal Trade Commission to investigate Facebook's privacy approach, echoing the concerns of a coalition of privacy groups that has filed two complaints with the agency asking it to look into the social network.

Kenneth Corbin is an associate editor at InternetNews.com, the news service of Internet.com, the network for technology professionals.