Re: Have you really checked the numbers?
I gather from your explanation that you have experience at the sharp end and you may well be correct that this is not excessive.
However my view, and I'm sure many here share it, is that as things stand there is no due process in place that corresponds to a search warrant. In fact, it's worse; with a search warrant, unless the premises are unoccupied, the suspect parties will be aware of the action and could even challenge the warrant, is only in retrospect. Although some queries will be made in respect of a seized phone in many (?most) the subject will be unaware.
I think two things are needed to ensure that this is done right.
The first is that authorisation be taken out of the hands of a senior officer or minister - I cannot be persuaded that this is due process. It should be done by a disinterested party such as a magistrate or judge on the basis of reasonable suspicion.
Secondly there should be an oversight authority to review the results. Each investigation should, after a suitable interval, report the proportion of the requests which resulted in significant information. Investigations yielding an unexpectedly high proportion of negative results should be required to explanation by the investigation team. The authority should be responsible for publishing an annual report summarising this and providing more detailed feedback to the individuals who authorised the original requests - in part this would be to discourage regulatory capture.
A proper review process would require much more detailed information from the Police. For instance in the report referenced in the article only one force, Humberside IIRC, provided a breakdown of the types of crime suspected. One category was traffic offences. I'm guessing these would be suspected texting whilst driving or the like. If requests are made on the basis of reasonable suspicion, say a report that someone was seen doing this, one would expect a high proportion of the requests would produce evidence to support the suspicion - but not 100%. Sometimes the suspicion would be reasonable but mistaken and the result of the request would be to clear the suspect. Clearing an innocent person is as important a result as providing evidence of guilt in a criminal investigation. If, however, a force were to produce a lot of negatives in such a category the oversight authority would have to look at the possibility that the traffic officers were conducting fishing trips whilst the same level of negatives in a serious crime investigation might not be out of the way and investigation of seized, suspected stolen, mobiles would have yet a different expected level of negatives.