SAN FRANCISCO (KGO) -- The massive Facebook data breach involving Cambridge Analytica has many wondering how much Facebook knows about us. Now, a new study by Consumer Reports warns - it knows more than you may think.
Facebook collects more than the information you post on Facebook itself. In fact, the social media site is tracking your movements all across the internet.
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"It's safe to say if you have used or gone to a web page that has a like button on it, if you've ever shared something onto your Facebook profile, or if you use Facebook login, it's safe to say Facebook is tracking you," said Chris Raymond, deputy technology editor at Consumer Reports.
He says Facebook tracks you on sites that don't appear at all related to the social media site - everything from news sites to online shopping. Some tracking can happen when you're logged into Facebook and using the same browser to surf the web.
"it is essentially looking at each item you are reading, every story you're reading online any video you're watching online any product you're looking at and putting into your shopping cart,'' Raymond said.
However, simply logging off Facebook won't protect your data. There are other ways Facebook can track your activity. If you click on the Facebook "like" or "share" buttons that appear on other sites, Facebook sees that data and learns more about you.
Raymond says there are bits of coding embedded on other websites that send data to Facebook.
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CEO Mark Zuckerberg repeatedly said during testimony before Congress that Facebook does not sell that data outright, but uses it primarily to target ads to users, and sell the targeting ability to advertisers.
So what if you don't want to be tracked?
"There are ad blockers, sort of anti-tracking software that you can install on a computer that will limit some of that information that they get and some of the ads that are targeted at you,'' Raymond said.
Besides the blocking software, there are low-tech ways to protect yourself. Experts recommended using different emails and web browsers for different services online. And of course you can limit the amount and type of personal information you post online.
Consumers also may use privacy settings to avoid seeing ads, but that won't affect the ability of companies to collect and store their data.
Here's a link to more information in the Consumer Reports study: https://www.consumerreports.org/privacy/how-facebook-tracks-you-even-when-youre-not-on-facebook/
All Consumer Reports material Copyright 2018 Consumer Reports, Inc. ALL RIGHTS RESERVED. Consumer Reports is a not-for-profit organization which accepts no advertising. It has no commercial relationship with any advertiser or sponsor on this site. For more information visit consumer.org.
Facebook tracks you even when you are not on Facebook