Some, like Cubeyou, said they have been unfairly blocked from accessing Facebook users. Tinder, the dating app, discovered that its users were no longer able to log into the app using their Facebook accounts. Pod, a calendar syncing app, found that its users could no longer see Facebook events within their calendars. And Job Fusion, a jobs app that allowed users to see where their Facebook friends worked, announced that it was not longer able to offer its services within Facebook.
The fallout has cast a shadow over Facebook’s annual meeting with developers, which was scheduled to start on Tuesday in San Jose, Calif. The event, which includes a speech from Mark Zuckerberg, Facebook’s chief executive, is typically a major attraction for developers. But this year, half a dozen developers who had previously attended the conference told The Times that they did not plan to go because they objected to Facebook’s policy changes. Others who planned to be there said they intended to challenge Facebook’s leaders over the changes.
Facebook said it expected roughly 5,000 people — a record high — to be at the developer conference, which is known as F8. But the company also said it has tweaked the event with an eye toward data privacy. For example, the social network canceled the announcement of a Facebook smart home speaker to challenge Amazon’s Echo and Google’s Home amid worries that the device would raise more questions about the amount of data the company collects.
Ime Archibong, Facebook’s vice president of product partnerships, said developers are “incredible partners” for the company, but also added that it must “strike the right balance between creating compelling social experiences, protecting people’s data, and supporting an innovative developer ecosystem.”
Bhaskar Chakravorti, senior associate dean at The Fletcher School at Tufts University, said Facebook had to walk a fine line. “They have taken a blunt instrument approach, which is the right thing to do from a public relations standpoint,” he said. “But now they need to reach out to developers and smooth things over.”
For much of its history, Facebook has had a rocky relationship with developers. It has sometimes adopted policies to attract developers, including by opening access to its vast troves of user data. Developers, in turn, created apps that became emblematic of the Facebook experience — apps such as Farmville, a farming simulation game played with friends on the social network, which was made by the gaming company Zynga.
But developers are often at the mercy of any changes that Facebook decides to make. When Facebook clamped down on viral apps several years ago, it became harder for companies like Zynga to spread their games across the social media site. Zynga has since turned toward making mobile games and its fortunes have plummeted.
Facebook announced a series of privacy changes in early April. Under the new measures, developers can only see a Facebook user’s name, profile photo and email address; previously, the could see more information, like users’ Facebook posts. Facebook is also cutting off developers’ access to user accounts if someone has not used their apps for three months or longer. That policy is intended to prevent developers from collecting information in the background for months or years after people stop using their apps.
Facebook also announced that it was investigating apps that had gained access to large amounts of its data in the past, and said it was conducting an audit of any company that it believed has shown suspicious activity.
Cubeyou got caught up in the dragnet in early April. At the time, CNBC reported that the company, which is based in Redwood City, Calif., had collected users’ Facebook information for academic purposes and then sold the data to commercial firms without informing users. Facebook said it was conducting an audit of Cubeyou to determine if there was any wrongdoing.
Mr. Treu said Cubeyou fully complies with Facebook’s requirements of disclosing the data it collects and what that data is used for. He added that Cubeyou strips out any personally identifiable information that it gets from Facebook. Cubeyou is simply being singled out as part of “a witch hunt” by Facebook, he said.
“We did everything by the rules, and we are ready to prove that,” said Mr. Treu, who said his company has repeatedly reached out to Facebook to talk. “There is no way to talk to them, to find out anything.”