Wouldn't you really like to know? Asking this question marks you as a possible felon. So what do you expect? Walmart is very serious about protecting their merchandise and so you can expect that they do EVERYTHING possible to stop people who intend to steal. Hidden cameras, secret security people, and other things exist for this reason.

I BET they have many cameras YOU wouldn't see if someone pointed them out to you.

However, they are not actually hidden. In the isles with high theft items, they actually have monitors that SHOW YOU you are on camera, complete with a 'recording in progress' message. It is more efficient to discourage theft than to prosecute theft.

Yes. So do most stores. It's to catch shoplifters.

Not in the bathrooms. That's illegal. Anywhere else is ok. It would depend on the store.

I've had people tell me that they watch you up on top of the skylights even. Cosmetics has aisle cams, btw.