I suspect that this is to cover privacy issues. They don't want a repeat of what happened with the Netflix Prize. The Netflix Prize 2 was canceled because of the privacy issues involved with the data set (http://blog.netflix.com/2010/03/this-is-neil-hunt-chief-prod...).
The FAQ states that participants will be randomly audited to ensure that they are satisfying data privacy standards.
The FAQ states that participants will be randomly audited to ensure that they are satisfying data privacy standards.