I agree that this is nonsense... While it is true that they can provide clues as to who bought suitcases from them, the point is... WHY DO THEY NEED TO BE ARRESTED? The police is only making them more uncomfortable - as if they have committed any crime.
It doesn't appear that they had stitched the suitcase with bombs in it. The police should make them comfortable and let them remember who they gave the suitcase to. Instead they are looking for scapegoats.
As far as records of customers is concerned, HOW DOES THE POLICE EXPECT SUCH SMALL ENTERPRISES AS SUITCASE COVER STITCHERS TO KEEP CUSTOMER RECORDS? Does the police have to be taught the difference between the organised and unorganised sectors?
I also want the real culprits caught but with this kind of exercise, I don't think progress is being made in the right direction.