We don't keep any medications in our guest bathroom. DH put marbles in the medicine cabinet that would fall out if it were opened because we never opened it . Only once did the marbles come crashing down and the person was my daughter looking for a new tooth brush. She knew I always kept several for emergencies. She was so embarrassed. We decided not to do this any more. I was some what humiliated about the whole thing. It does make sense if you really want to spy on someone to do something like this.