If you’ve been to a store like CVS, Walgreens or Target in the last few years, you may have noticed a trend: more and more essentials are locked up behind plexiglass walls. The strategy started as an anti-theft measure. But there’s little evidence that it’s worked.

On today’s Big Take podcast, Bloomberg’s Amanda Mull takes host Sarah Holder through the causes and consequences of the retail lock-up era — and how it’s changed the way we shop.

Read more: Retailers Locked Up Their Products—and Broke Shopping in America