One company has already been caught snooping and selling user data...
TV manufacturer Vizio has been fined $2.2m in the US for spying on smart TV users and selling this information without their permission.
This case involved the company's 11 million smart sets sold since 2010 - and has raised questions about what information our TVs are hoovering up.
The company was using 'Automatic Content Recognition' to capture the images on screen to track what content was being watched by individual users. This started in 2014 - and users viewing habits were tracked and matched to their IP addresses.
The Federal Trade Commission (FTC) in the US ruled it was gathering, "as many as 100 billion data points a day."
"Consumers didn't know that while they were watching their TVs, Vizio was watching them ... The generic way the company described that feature – for example, 'enables program offers and suggestions' – didn’t give consumers the necessary heads-up to know that Vizio was tracking their TV’s every flicker," the FTC continued.
This information was shared with advertisers and linked to IP addresses. Identities were withheld but users' ages, sex, age and other pieces of personal information were included.
Vizio acknowledged that it was in the wrong, and said that this information was aggregated, "to create summary reports measuring viewing audiences or behaviors."
Other manufactures are known to be tracking data, but they say it is to not shared with other parties and you can opt-out of this data gathering (here's a brand-by-brand guide).
The overall advice is that if you're concerned about your privacy it's best to stick to an offline TV (or to take your smart TV offline) and to use an external devices like an Apple TV or Chromecast to stream your favourite shows.
The Apple device doesn't gather much information - and the Google device comes with the company's normal T&Cs and is connected to your broader Google account.