There are two reasons: 1) It drives your customers to your competitors If you had a choice between a shop that detained you in an "interview room", and checke

There are two reasons: 1) It drives your customers to your competitors If you had a choice between a shop that detained you in an "interview room", and checked your bags, pockets and body cavities against the receipt, every single time you went there, and one that just had a few CCTV cameras, which would you choose? 2) It makes people think "If I'm going to be punished anyway, I might as well commit the crime" In some countries (IIRC, both Finland & Netherlands do this), purchasers of recordable media are "treated as criminals" and pre-emptively fined for copying music (specifically music, not software). If I were subject to that kind of treatment, you bet I'd copy as much music as I could lay my hands on.