re: Is Walmarks checking bags these days?

Public service announcement: Walmart has no means or ability to stop you and force you over to the side as you’re leaving and inspect your bags. If they have probable cause to suspect that you have stolen something, they can call the police. But they don’t. They are just checking everyone and that is not legal.

Costco and Sam’s can get away with this to a degree because they are a private membership club. Not complying with their provisions can result in you being kicked out of the club but they have no legal mechanism to detain you or force you to stop to inspect your receipt.