OK, maybe.
If used only in situations where the police would normally have reasonable justification for demanding a person's identity (because they have an interest in a particular person who is on their system), then it is a useful idea.
If used without reasonable suspicion then it is a step towards unacceptable (in the UK at least) demands for ID.
Furthermore, the reports don't state what happens to the print at the server end. If it is stored along with any identity info given, then it is a sneaky expansion of the fingerprint database.