Facebook and some of the other largest technology firms in the world faced sharp criticism on Wednesday for failing to disclose the extent of the social network’s data-sharing deals, many of which went back to the company’s early years.
Details of the deals, revealed in a New York Times report on Tuesday, set in motion a fresh round of rebukes from legislators who had singled out Facebook’s sharing practices in the recent past. And they came at a moment when the Trump administration, Congress and even some Silicon Valley executives are calling for stricter privacy laws that would govern Facebook and other businesses that trade in huge amounts of personal information.
Lawmakers in the United States and Britain on Wednesday called for greater oversight of Facebook, the world’s dominant social media platform. But critics also focused on statements that Facebook’s chief executive, Mark Zuckerberg, had made in recent months while defending the company.
Senator Roy Blunt, the Missouri Republican, said the revelations made him question Mr. Zuckerberg’s decision making. “I know he’s smart, but sometimes I think he’s got no sense,” Mr. Blunt told Fox News, adding that the disclosures were cause to consider stricter privacy laws. “Congress is going to have to regulate them and stop this, and I hate to do it, but by God I will if they can’t clean up their act.”
The outcry came in response to The Times’s findings that Facebook had granted business partners, including Microsoft, Amazon and Spotify, more intrusive access to user data than it had divulged — allowing some partners access without users’ permission. Last June, The Times uncovered a subset of Facebook’s partners, all of them device makers, that pulled user data onto smartphones and tablets.
Facebook officials said the deals did not violate user privacy — or a 2011 consent agreement with the Federal Trade Commission that barred it from sharing data without permission — because the companies were acting on Facebook’s behalf.
In a post published on Facebook on Tuesday, Konstantinos Papamiltiadis, the company’s director of developer platforms and programs, defended the partnerships, saying the company entered into the agreements to let users interact with Facebook friends across devices and popular websites.
“None of these partnerships or features gave companies access to information without people’s permission,” Mr. Papamiltiadis wrote, asserting that most partners did not have to seek consent before obtaining users’ data because they were serving as extensions of Facebook.
But he also acknowledged that Facebook had made mistakes in managing some of the deals. “We recognize that we’ve needed tighter management over how partners and developers can access information,” he wrote.
Facebook was already dealing with fallout from reports that a political consulting company, Cambridge Analytica, obtained the personal data of tens of millions of Facebook users. Cambridge used the information to build tools later deployed in President Trump’s election campaign. The F.T.C. launched an inquiry into Facebook’s practices after the data leak became public, and the Justice Department and Securities and Exchange Commission are also investigating the social network.
News of the deals on Wednesday further roiled the technology industry as policymakers and privacy advocates directed anger at Facebook’s leaders and its partners.
Senator Ron Wyden, the Oregon Democrat, attacked Mr. Zuckerberg for not disclosing the full scope of the agreements during a Senate hearing in the spring, when Mr. Zuckerberg assured officials that users had complete control of their data.
“Mark Zuckerberg had a lot of chutzpah telling Congress that Americans could control their data, when seemingly every other week Facebook faces a new privacy scandal for abusing our personal information,” Mr. Wyden said.
Senator Richard Blumenthal, the Connecticut Democrat, called for the F.T.C. to police the company more aggressively. “Facebook’s seemingly unrestrained sharing of user data is the privacy equivalent of the BP oil spill,” Mr. Blumenthal wrote on Twitter. “Ongoing, uncontained & toxic. We will be paying the price for decades.”
Damian Collins, a British lawmaker whose parliamentary committee is investigating online disinformation, said Facebook officials should answer for why they had not been more forthcoming. “I feel that we have been given misleading responses by the company when we have asked these questions during previous evidence sessions.”
And Barbara Underwood, the New York attorney general, said her office would examine the deals as part of a continuing investigation into Facebook. “The news that Facebook struck data-sharing partnerships with other corporations reflects the many unanswered questions to which New Yorkers deserve clear answers,” said Amy Spitalnick, a spokeswoman for Ms. Underwood’s office.
Facebook has sought to contain the damage in part by winding down many of its data-sharing partnerships. Facebook said on Wednesday that it had brought more than 60 of its agreements to a close.
But deals with two giants of the technology world — Amazon and Apple — remain in place. Facebook officials said the deals must continue because of contracts the social network signed with the companies.
Records obtained by The Times showed that the social network granted Apple devices broad access to people’s personal data, even when users had disabled sharing. Facebook gave Amazon access users’ email addresses without permission, among other things, the records revealed.
An Amazon spokesman did not respond to a request for comment. An Apple spokesman said that the company stopped integrating Facebook into its operating systems earlier this year, but that the access continued to accommodate users of older systems.
In addition to those partnerships, Facebook will continue allowing special access for Tobii Technology, a company that makes devices allowing people with neuromuscular diseases to use the social network, a Facebook spokeswoman said.
Facebook also had a deal to share the data of users’ friends with Microsoft, and agreements that gave Spotify and Netflix full access to users’ private messages. Users were especially incensed at the Spotify and Netflix deals, which appeared to go far beyond what the companies required for their integrations.
Spotify’s Facebook feature, still active, allowed users to share music with friends; Netflix’s integration, discontinued in 2015, let users share movie and TV recommendations. A Netflix spokesman on Wednesday said the company did not view personal messages for any other reason.
“This story exposes the myth of control,” Kate Crawford, a founder of the A.I. Now Institute at New York University, wrote in a tweet referring to Facebook’s partnerships with Spotify, Netflix and other companies.
“The total lack of respect for user wishes is the infinitely repeating scandal of 2018,” she added.