Facebook is very much the social networking underdog in South Korea, and a warning from the country's privacy commissioner will not help it grow.
The Korean Communications Commission said Facebook was in breach of Korean data protection law and has 30 days to respond to the complaint.
The regulator said Facebook needed to get explicit consent from users in order to collect their information. Facebook's Ts&Cs cover data privacy, or the lack of it, but the regulator wants this made much clearer to users, IDG reports.
Korea has an extremely tech-literate population coupled with excellent internet access, and it has been into social networking for far longer than Mark Zuckerberg.
Its home-grown equivalent to Facebook, Cyworld, has signed up most of the nation's population already - it has 16 million members compared to Facebook's two million in the country. When the Reg visited Cyworld HQ, the site was getting 22 billion page impressions a month.
Despite its early and massive success the site has struggled to compete internationally. Launches in the US and Germany were quickly abandoned although the company has had some success in China and Vietnam.
Cyworld's popularity has dropped a little since its peak when it claimed virtually every Korean between 18 and 25 as a member.
Users get a "minihompy" (mini-home-page) which they can link to their friends' pages. Revenue comes from the sale or rent of virtual decorations for the page, background music and mobile access.
Facebook has a month to respond to the complaint and either make more explicit what information it is collecting or at least show the regulator a plan of what it intends to do.
If it fails to do either of these things, the regulator could either fine Facebook or take other measures against it. ®
The Korean Communications Standards Commission homepage starts with a message from its chairman: "I would like to express my sincere appreciation and warm greeting to you for visiting the Korea Communications Standards Commission with love and interest." A cheery welcome on a cold winter's morning.