According to consumer reporter Asa Aarons, unless you’ve signed a membership agreement contractually obligating you, bag searches and receipt checks are voluntary. As in, you can refuse.
If the retailer has a reasonable suspicion you’re shoplifting, however, they can detain you at will. — BEN POPKEN
Bag check at store exit makes shoppers see red [NY Daily News] (Thanks to David!)
Previously: Do I Have To Let Stores Check My Receipt?