This week, Vizio, one of the biggest makers of internet-connected televisions, agreed to pay $2.2 million to settle charges that it has been collecting and selling viewing data from millions of TVs without the knowledge or consent of the sets’ owners. The charges, brought by the Federal Trade Commission and the New Jersey attorney general’s office, have some serious implications for consumers and smart TV makers.

Here’s what you should know.

What data did Vizio collect?

Vizio, which has sold more than 11 million internet-connected TVs since 2010, and its data arm earns money by licensing people’s TV viewing information in three main ways, according to a complaint from the agencies.

One is through audience measurement — showing what programs and commercials people watched, along with how and when they viewed it. Another is from gauging the effectiveness of advertisements, including the ability to “analyze a household’s behavior across devices,” using the IP address attached to all the internet-enabled gadgets in a home. That could mean tracking whether someone visited a website on their laptop after seeing a fast food commercial, or if an online ad motivated them to watch a TV show. The third is by targeting ads to people on other devices, like phones or tablets, based on what they watched on TV.