's new Echo Show, which begins shipping to customers this week, has a really creepy feature.

It's called "drop in" and lets preapproved users suddenly appear on your Amazon Echo for two-way video chats. You don't answer the video call, your friends and family can just drop right into your home.

Sounds like something out of a 1980s or 1990s sci-fi film, doesn't it?

The drop-in option is off by default, since you'll need to approve folks who can just pop into your house, but you should probably take a moment to consider it before activating

Just think: It seems compelling, maybe even fun, to activate drop in so that your parents can pop up on the video camera and interact with their grandchildren. That would be exciting maybe once or twice, until they drop in while you're poking through the fridge in your underwear. There goes your privacy.

Worse, what happens if hackers are able to get access to that camera? That's even scarier to think about, though it's a vulnerability that all smart cameras are prone to, whether they're made by Amazon, Nest or Logitech.

"Drop In is an optional feature for Alexa customers to enable and use," an Amazon spokesperson told CNBC. "If customers decide to enable it, they have the option to turn on Do Not Disturb on one, or all, of their devices, which will block calls and messages from coming in. Customers will know when they are in a Drop In call as they will first hear a 'chime' and the green light on their Echo device will rotate throughout the call. The Drop In feature is especially useful for household communications such as intercom functionality or in specific scenarios where customers may want to drop in on their aging in place relatives or check in on the baby's room while out for the evening."

The good news is that the Amazon Echo Show is useful for plenty of other tasks. It offers a display for viewing the weather, music lyrics and even videos. It supports Alexa so you can ask all sorts of questions. It can even tap into other video cameras to provide live feeds, in case you want to see who's at the door, for example.

The drop-in feature is probably one I'll never use and it's one you might want to think twice about before activating.