Facebook finally rolled out a “clear history” button that lets people erase their online tracks, adding to the potential roadblocks advertisers face targeting consumers as more internet companies lockdown data.

On Tuesday, Facebook made “Off-Facebook Activity” available to all its users, after only releasing the privacy measure in a limited way last year. The option is available in people’s settings menu on the social network, and it leads to a list of brands that have data on the user. People can see if brands—Hulu, J. Crew, Home Depot and any mass marketers—have shared data with Facebook.

Facebook users can also delete the data, so that the brand could no longer use that connection as a way to target the person with ads. It’s similar to clearing the internet activity in a browser and erasing cookies, which are the software files that keep logs of what sites a person visits and other behavior.

By erasing these tracks, advertisers have a hard time retargeting the consumers that visit their websites, log into their apps and make purchases in their stores. It also makes it difficult for advertisers to keep track of their marketing campaigns. If a person deletes their online tracks, a brand might not be able to tell if and when they served that person an ad, and whether that ad was effective.

However, it remains to be seen how many Facebook users are interested in managing their settings to erase the data. Advertisers say adoption among the public will be limited, so they are not overly concerned. “I don’t anticipate this getting sufficient scale to really impact our business or our clients’ business,” says George Manas, president and chief media officer of OMD U.S.

"Consumers have a track record of apathy when it comes to actively managing their privacy,” says Aaron Goldman, CMO at marketing technology company 4C. “Whether it's deleting cookies or clearing history, these tools typically get very little usage and have very little impact on marketers.”

Facebook CEO Mark Zuckerberg anounced the new privacy tool in a blog post on Tuesday. Facebook has made a number of changes to the way it handles users’ data and how that data affects advertising. The company is responding to a more vigilant privacy environment in the U.S. and around the world, where there have been concerns over how internet companies protect people’s personal information. Europe led the way with General Data Protection Regulation in 2018, and it was followed by laws in the U.S., like the newly enacted California Consumer Privacy Act.

Facebook also has been under a microscope since Cambridge Analytica was exposed in 2017. The third-party data company abused the social media information of up to 87 million users. Last year, Facebook settled the privacy breach for $5 billion with the Federal Trade Commission.

In 2018, Facebook banned third-party data providers like Acxiom, Experian and Epsilon, kicking them off its automated ad platform, so brands could no longer directly access their data to create targeting audiences. It was a sign that Facebook would be stricter with how brands use consumer data to reach users on its platform.

Facebook has warned that with less data available for ad targeting, its ads might be less valuable with brands willing to pay less for them. On Wednesday, Facebook is set to release its fourth-quarter earnings report.

Google and Apple have made privacy enhancements, too, which affect the digital advertising world. Apple has been the most aggressive, with anti-tracking mechanisms in Safari web browser, which prevents brands from connecting the dots as people bounce around the web through cookies. Earlier this month, Google announced it would take a cue from Apple and phase out third-party cookies within two years.

The changes in how data is collected and shared could wind up helping the top internet advertising companies like Facebook and Google, while squeezing out the companies that build advertising technology businesses based on the old system. If Google and Facebook control the data more tightly, advertisers say, then brands are more beholden to them to run their campaigns.

“These moves while they’re being done in the spirit of consumer data privacy standards,” Manas says. “They are also pretty clearly advantageous to a Facebook, Google, Amazon and other major platform players who own and operate an ecosystem that is essentially one giant first-party data ecosystem.”

Brands and their ad tech partners are coming up with new ways to retrace the digital footprints back to consumers while working within the new privacy framework, says Goldman of 4C. “The trend in the industry is definitely moving towards more of a privacy focus and brands need to have strategies in place to target their most valuable customers without relying on second or third-party data," Goldman says.