Some of the information, like device type, city, and state, is hardly unique to one user. But other data, like the device serial number, Wi-Fi network, and advertising ID, could be used to pinpoint an individual. “This gives them a more complete picture of who you are,” said Moghaddam. He noted that some channels even sent unencrypted email addresses and video titles to the trackers.In total, the study found trackers on 69 percent of Roku channels and 89 percent of Amazon Fire channels. “Some of these are well known, such as Google, while many others are relatively obscure companies that most of us have never heard of,” Narayanan said. Google’s ad service DoubleClick was found on 97 percent of Roku channels.
“Like other publishers, smart TV app developers can use Google’s ad services to show ads against their content, and we’ve helped design industry guidelines for this that enable a privacy-safe experience for users,” a Google spokesperson said in a statement emailed to The Verge. “Depending on the user’s preferences, the developer may share data with Google that’s similar to data used for ads in mobile apps or on the web.” Both Roku and Amazon Fire allow users to turn off targeted advertising. But doing so only stops a user’s advertising ID from being tracked — not the other uniquely identifiable information.
“Better privacy controls would certainly help, but they are ultimately band-aids,” Narayanan said. “The business model of targeted advertising on TVs is incompatible with privacy, and we need to confront that reality. To maximize revenue, platforms based on ad targeting will likely turn to data mining and algorithmic personalization/persuasion to keep people glued to the screen as long as possible.”