A German data protection official has launched an investigation into how Facebook handles the personal information of people who are not a part of the social networking site.

Johannes Caspar, head data protection in Hamburg, has received complaints about the process by which Facebook lets users invite non-Facebook users to the service, the Los Angeles Times reports.

Users can opt to have Facebook scan their e-mail contact list and display those users who are not on Facebook. As a result, Caspar said Facebook is keeping information about people with whom Facebook does not have a relationship, which is against Germany's data protection law.

Facebook said they are reviewing the complaint.

Originally posted to AppScout.