Yes, there can be other code stickers or sensors and the cameras are a big problemDon't have a conversation about whether or not he can get caught, have one about the huge difference between right and wrongStealing from ANYONE is a big no-no.
Because i have worked in a retail shop and i had to stop many of the customers who used to go past the door and it used to make a bleep noise and this was because their was tags on the items that the customers didn't know about and only staff know about it as they take the tag off for you at the till when your buying the itemSo my advice from experience to your friend is not to do that because their are many other security tags that the customers don't know about.
Yes because of the security cameras and sometimes there are other sensors on or in it.
Absolutley you canThere are people who work in Loss Prevention watching on the sales floor, by security cameras, and through double mirrors Also the sensors are not always controlled throught the bar codesThere are magnetic sensors that are inside CD's, DVDs, boxes, etcThere are also sensors on clothing and shoes Regardless of whether or not you think you've found a way to defeat the sensor system, how about you don't do it because it's wrong?