Facebook faced criticism over the changes when they were made last December, and more when it announced recently that it would allow business partners to make more use of members' data.
The Article 29 Working Party, the committee comprising the data protection regulators of the European Union's 27 member states, has added its voice to the criticisms and has written to Facebook to express its alarm at the changes.
"It is unacceptable that the company fundamentally changed the default settings on its social-networking platform to the detriment of a user," said a statement from the Working Party. "Facebook made the change only days after the company and other social networking sites providers participated at a hearing during the Article 29 Working Party’s plenary meeting in November 2009."
Facebook's changes last year involved changing the default privacy settings on its service. Though users were asked to confirm the changes, default settings are seen as important because many users simply confirm the pre-selected options.
Facebook users can set their profiles, which contain status updates, messages, pictures and more, to be seen by anyone on the internet or just by members of networks they join or just by their 'friends' within the service.
Users who accepted Facebook's new defaults found that much more of their information was available to everyone or to members of very large networks than before. They found that details of their family, relationships and employer were available to the whole internet. Accepting Facebook's changes would also make their birthdays and religious views available to any Facebook user who is a friend with one of their friends, and their phone numbers, physical addresses and email addresses available to all their friends.
Facebook claimed that the changes were a simplification, but digital rights group the Electronic Frontier Foundation (EFF) said that they created "new and serious privacy problems".
"These new 'privacy' changes are clearly intended to push Facebook users to publicly share even more information than before," said the EFF's Kevin Bankston at the time. "Even worse, the changes will actually reduce the amount of control that users have over some of their personal data."
The Article 29 Working Party has now added its voice to the criticism. It said that in its letter to Facebook it had emphasised that default settings should protect, not expose, users' private information.
"The Working Party emphasised the need for a default setting in which access to the profile information and information about the connections of a user is limited to self-selected contacts," said its statement. "Any further access, such as by search engines, should be an explicit choice of the user."
The Working Party has written to 20 social networking companies to highlight concerns it has about the operation of services overall.
"The letters … address the issue of third-party applications," the statement said. "Providers of social network services should grant users a maximum of control about which profile data can be accessed by a third party application on a case-by-case basis."
"The Article 29 Working Party also raised the issue of data of third persons contained in users' profiles. Providers of social networking sites should be aware that it would be a breach of data protection law if they use personal data of other individuals contained in a user profile for commercial purposes if these other individuals have not given their free and unambiguous consent," it said.
The changes are also the subject of a complaint by privacy activist group the Electronic Privacy Information Center (EPIC), which has complained about them to US consumer regulator the Federal Trade Commission.
"These changes violate user expectations, diminish user privacy, and contradict Facebook’s own representations. These business practices are Unfair and Deceptive Trade Practice," said its complaint.
Facebook last month announced a new initiative at its F8 conference designed to make even more use of individuals' data than before. Users' preferences, likes and activity would be visible to Facebook business partner sites.
While Facebook called the developments 'social plug-ins' and claimed they woujld improve people's online experiences, users and privacy activists have expressed concerns about the implications of the changes.