Google did not respond to a request for comment.

The topic didn’t suddenly materialize this year — The Wall Street Journal broke major ground on digital surveillance with its award-winning series “What They Know” in 2010.

But at that time Facebook was not yet public and Google was a fraction of its current size. Digital tracking has since become far more pervasive and intertwined with peoples’ daily lives — advertisements follow them from their computers to their phones and even their TVs — and often, it can feel inescapable. Recently, Facebook told Gizmodo that even if people opt out of location sharing with the social network, it can still determine their location and use it for targeted advertising.

“There are so many aspects of how companies deal with the public that obfuscates what actually goes on and so many attempts to placate people using jargon,” Professor Turow said. “I’ve spoken to lawyers who write privacy policies who admit — they admit — that they aren’t written for the public.”

In their survey this year, researchers led by Professor Turow found that most Americans did not understand privacy policies on websites. More than half did not know the correct answer to this true-or-false statement: “If a website has a privacy policy, that means the site won’t share user information with other sites or companies without permission.” (The statement is false.)

The researchers also found that most Americans did not know that companies can legally collect and keep personal data on 13-year-olds as if they are adults. Companies are able to do that because the Children’s Online Privacy Protection Act, a federal law, extends only to children who are 12 and under.

“I would argue that’s because people can’t imagine that the law would allow this kind of attitude,” Professor Turow said. The researchers conducted national surveys in 2015 and this year, working with two polling companies to interview a representative sample of Americans on their landlines and cellphones.

The findings are particularly notable as tech companies and marketers argue that individuals should be responsible for understanding and navigating all of these policies and their privacy settings. Some people may delete Facebook, but what about Instagram and WhatsApp? Avoiding Google for search purposes is one thing. Then try avoiding Gmail, YouTube and Waze.