Shopping carts are expensive and are frequently stolen, costing retailers hundreds of millions of dollars worldwide each year.
Low-tech methods of preventing theft, such as installing barriers in parking lots or charging a small deposit for carts, have been used.
More high-tech solutions employ smart cart locks controlled by wires or magnets to set off alarms or lock wheels, but these are expensive to install and can be bypassed.
Interestingly, these high-tech locks are easily hacked as they operate in the audible frequency range, and phone apps are already available that can lock and unlock shopping carts.
The patent for the smart cart lock system was filed back in 1968, so it is surprising that modern systems still use such easily hackable technology, and it would be interesting to see if more modern solutions will be developed in the near future.
