I tend to agree. Smacks of trawling for information to make a case for suspicion, as opposed to having enough evidence to make a case for the CPS.
Waste of Police/CPS time and resources.
I’m assuming every Joe in the street can also refuse PIN , as their ‘crimes against society’ will have no overlap into anything that can have Terrorism label slapped on and won’t be obstructing an investigation like that. Otherwise... “caught speeding Sir, can we have your phone PIN. You seem to fit the profile for car cruising”.