Facebook has again tweaked its News Feed, this time in a major way. The social media giant will now prioritize what a member’s friends and family share and comment on, rather than content from publishers and brands. The change, meant to maximize what chief executive Mark Zuckerberg calls “meaningful interaction,” will take place over the next few weeks. Likewise, Facebook wants to diminish “passive content,” which is defined as that which requires nothing of the viewer than to sit back and watch or read.

The New York Times reports that, “the shift is the most significant overhaul in years to Facebook’s News Feed.”

“We want to make sure that our products are not just fun, but are good for people,” said Zuckerberg. “We need to refocus the system.”

Despite the good intentions, said NYT, “bogus news may still spread” if a relative links to it, and communicating only with friends and relatives could amplify the likelihood of reinforcing the user’s existing ideology. The move is seen largely as a response to the charge that, the “site has negatively influenced millions of its users.”

Facebook also revealed that, “Russian agents had used the social network to spread divisive and inflammatory posts and ads to polarize the American electorate.” Facebook will appear at another Capitol Hill hearing, along with Twitter and YouTube, about “the online spread of extremist propaganda.”

By diminishing the posts of publishers, however, the News Feed changes will “almost certainly” negatively impact “publishers, nonprofits, small business and many other groups [that] rely on the social network to reach people.”

Elsewhere, NYT reports that, “if you think about Facebook’s primary service as free cookies rather than social networking, the underlying difficulties with the plan become obvious, and even existential,” noting that Facebook’s stock fell 4.5 percent after its announcement. Zuckerberg’s motive is to move away from the kind of “social networking [that makes] people feel bad about themselves,” and move to deeper sharing — defined as “sharing messages, posts and comments with close friends and reminiscing about past interactions” — that actually “improves a person’s well-being.”

Facebook also admits, however, that, “people are likely to spend less time on the service” sporting the updated News Feed. According to Pivotal Research analyst Brian Wieser and Nielsen, “American adults spent about 37 minutes a day on Facebook in September.” Facebook has likely modeled how its News Feed changes will impact engagement. But “what Facebook can’t predict is how … users, advertisers, investors and competitors will alter their behavior in the face of a less immediately engaging News Feed.”

The Wall Street Journal notes that, “advertisers are all too familiar with Facebook’s routine algorithm changes.” But this most recent change will make it “virtually impossible for Facebook users to see companies’ organic posts — those distributed by brands without paying to promote them,” which will “likely drive up ad prices and push companies to consider other advertising vehicles on Facebook.”