Walmart rolled out self-checkout to streamline operations and reduce labor

But employees and customers say it's causing a surge in thefts

Walmart CEO Doug McMillon said stores could close if the rising tide of theft isn't stemmed.

Customers and employees blame self-checkout, which Walmart has increasingly relied on, for theft.

A theft expert said automation "inherently means there's going to be less eyes on a transaction."

Walmart still utilizes cashiers at stores across the nation.

Walmart declined to answer questions on its ratio of self-checkout kiosks to traditional checkout lanes

About 1% of its US revenue — or roughly $3 billion every year — to stealing by customers and employees.