A fundamental principle underpinning research involving human subjects is the need for informed consent. The need for informed consent from research participants is stated in the Declaration of Helsinki [[5]] and reflected in our editorial policies [[6]].
The Facebook study states that, as all users agree to their Data Use Policy prior to creating an account, they have given informed consent to participate in this research [[3]]. Facebook’s Data Use Policy states that they may use the information about their users “for internal operations, including troubleshooting, data analysis, testing, research and service improvement” [[7]]. It is our interpretation that this does not include research for external publication. It is also not possible to guarantee that those posting were aware of this statement, and therefore that their data could be used in scientific research.
Internet-based research also raises issues surrounding data protection and participant privacy. This is particularly a problem when data that was posted on the internet for other purposes is then used for research. The assumption is that, if information is posted on the internet and in the public domain, it can be considered available for use for any purpose [[4]]; but how far are participants aware of this assumption when they post their data? This becomes particularly problematic if research subjects are children or other vulnerable groups who may post information about themselves without understanding the extent to which their information could be disseminated or used. While individual countries have regulations, such as the Data Protection Act in the UK [[8]], that control the use of private data, there needs to be a global consensus on the use of publically accessible data when the extent of the owners’ (the study participants’) awareness of its use is unclear, especially when the participants are from a country that is different from the researchers’ or are a vulnerable group.