Google is closing a loophole that revealed when people were browsing in “incognito” mode, but the fix will leave some publishers defenseless against a certain breed of freeloading readers who can now jump their paywalls.

By the end of July, Google says it will patch the glitch in its Chrome web browser, which allowed websites to detect when a person was browsing incognito. “This will affect some publishers who have used the loophole to deter metered paywall circumvention,” said Barb Palser, Google’s partner development manager for news and web partnerships, in a blog post about the change.

While a small tweak, this latest move by Google is just another in a long line of updates that provide more anonymity to users but also impact the way publishers do business.

In recent months, Apple, Google and Facebook have all taken steps to limit data tracking across their services, making it more difficult for publishers and advertisers, but more accommodating to user privacy. Google, for instance, has been beefing up privacy controls on Chrome, following in Apple’s footsteps, letting web users prevent sites from tracking online behavior. Facebook is developing a “clear history” button that would let users erase data that connects them to web visits and advertisers outside the social network.

Google is telling these publishers, which include news sites such as The New York Times and Washington Post, to come up with new strategies for protecting paywalls.

Here is what publishers and readers should know:

What is incognito mode?
“Incognito mode is a private browsing mode where certain behavior is different from the normal browsing mode,” says Lukasz Olejnik, independent cybersecurity advisor and research associate at the Centre for Technology and Global Affairs at Oxford University. “The most visible difference is that upon closing the browser window the browser state is not retained. This means that cookies or visited sites are not saved.”

Incognito mode affords internet users some privacy, because the sites they visit can’t track their previous browsing history. However, there has been some confusion among consumers about exactly how much privacy they retain when they select “incognito” mode. “Users expect it to do more than it actually does,” Olejnik says.

What was the loophole that exposed “incognito” users?
There was a tell that signaled to websites when a visitor was browsing in that mode. So even if the site couldn’t connect that user to a prior web visit, they could see the visitor was incognito.

How does that affect publishers?
“It makes it harder for publishers,” says Daniel Hallac, New York Magazine’s chief product officer. “The technology that blocks readers in incognito mode will be over. That entire technology, not giving access to the site, publishers won’t be able to use that tactic.”

Readers had discovered that “incognito” mode protected them from some metered paywalls—online stop signs that pop up after a visitor views a certain number of articles. If the sites can’t see what a person visited before, they can’t keep tabs on how many articles they read.

Browsing incognito is similar to browsing after clearing one’s internet history of cookies, which are the tracking codes websites leave on browsers to compile information on visitors.

Publishers have found ways to detect when visitors enable private browsing mode and prevent them from accessing articles without becoming paid subscribers.

What will publishers do now?
Publishers could take this as a sign to rethink their paywall strategies, according to Claudius Senst, head of consumer subscriptions at Business Insider. The change won’t affect Business Insider’s paywall, Senst says, because the site doesn’t have a meter on the number of articles a visitor can read. It puts a paywall only on select stories it makes available exclusively to readers with Business Insider Prime memberships, which cost $99 a year. “Those stories can only be accessed by our members,” Senst says. “It’s not story count that matters, but story type.”

Readers can still find ways around the hard paywall, too, with certain browser tricks that make stories visible, Senst acknowledges. However, he says publishers should stop playing cat-and-mouse games with readers determined to get around the constraints, and just show these readers how much more there is to offer if they become paying members.

“I applaud everyone for finding a way around [the paywall],” Senst says. “They’re getting teased in, and the goal is to get them signed up.”

This article is published in collaboration with Adage.com