Yes, I certainly think transparency is important. We should aim for the situation where members of the public can understand how these technologies are being used; how they could be effective; how they could be affected by them; and how they may have been affected by them.
We know from studies of the use of these technologies in the U.S., for example, that there's very little in terms of an audit trail, and I think auditing the use of face recognition technologies is going to be an important part of using them more widely.