Well, such a release should of course be limited, regulated and with oversight. But I'd argue that at least police should have some possibility to get at custom

Well, such a release should of course be limited, regulated and with oversight. But I'd argue that at least police should have some possibility to get at customer data, even without opt-in. Release of privacy-sensitive data to other companies should strictly be by clear customer opt-in, with clear limits on its use. And even some of that should be forbidden for semi-monopolies such as telecom providers.