One kind of accusation? Do you mean the kind of accusation in which the only evidence that a crime ever took place is the statement of a single witnesses? It doesn't seem unreasonable that you'd want to investigate the credibility of the witness in such cases. I certainly wouldn't stop at rape accusations.
However, I think I'd prefer to see a court, rather than just the police, decide what data should be obtained/requested and how it should be used.
I suspect that in some of these cases the police think it's a hopeless case and are looking for a justification for dropping it. They are perhaps thinking: if this person really wants us to prosecute, then, OK, we'll do it, even if it seems hopeless, but if they won't even fully cooperate by letting us examine their phone then we really can't be bothered any more because we've got lots of better cases to be working on.
However, I think I'd prefer to see a court, rather than just the police, decide what data should be obtained/requested and how it should be used.
I suspect that in some of these cases the police think it's a hopeless case and are looking for a justification for dropping it. They are perhaps thinking: if this person really wants us to prosecute, then, OK, we'll do it, even if it seems hopeless, but if they won't even fully cooperate by letting us examine their phone then we really can't be bothered any more because we've got lots of better cases to be working on.