Pretty much everyone these days has a smartphone, a laptop and some kind of online social media presence, but few of us fully understand the implications of using that tech or the related potential privacy and security concerns.

Ads follow users around online, phones spy on us while we’re sleeping and even our TVs are tracking us. Yet most Americans don’t know that private browsing modes hide online activities only from someone else using the same computer. Few can correctly identify an example of true two-factor authentication, a security measure experts say is one of the most important ways users can protect sensitive information.

That makes it difficult for average tech users to make the right decisions about what data to share, what information to believe and how to protect themselves online.

Fred Turner, a communications professor at Stanford University, said the country’s technological literacy has struggled to keep pace with the speed with which digital tools have grown increasingly complex and opaque. “What you see is not at all what you get,” said Turner, who has been calling for better digital education.

Users are grappling with these issues as social media giants have been rocked by privacy scandals.

In September, Facebook said that tens of thousands of apps were suspended from its platform for possibly mishandling user data. That followed last year’s revelation that political consultancy Cambridge Analytica had improperly accessed personal data from 87 million Facebook users.

And three weeks ago, Twitter said it may have mishandled an unknown number of users’ e-mail addresses and phone numbers, allowing them to be used “inadvertently” for advertising purposes.

A June Pew Research Center study on data privacy, cybersecurity and social media topics found that people with more education had greater digital knowledge. Younger people fared better than older people, but the gaps were less stark than those found with educational attainment.

Monica Anderson, a co-author of the report, said previous Pew studies have found that the majority of Americans use social media websites, primarily Facebook. Yet the June survey showed that only 29% of those surveyed knew that Facebook owns Instagram and WhatsApp.

Facebook purchased the Instagram photo- and video-sharing service in 2012 for $1 billion and acquired messaging company WhatsApp for $16 billion two years later. In August, Facebook confirmed a report by the online outlet the Information that said the company was renaming the two services “Instagram from Facebook” and “WhatsApp from Facebook.”