I've got a bag with a key chain inside but I attach it to my purse. Good peace of mind!
Years ago, I was mooching around Littlewoods in town. I became aware someone was watching me. I reckoned it was a store detected. So, I walked, being followed, around every counter very slowly and eventually left without buying anything!
More recently, I was trying on a 'dressy' jacket in M and S. They didn't have my size so I was trying on the bigger and smaller sizes in front of a mirror. Again, I realised I was being rather surreptitiously watched! Eventually the woman came towards me. To my surprise she said she thought the jacket really suited me!!!!!