In an internal memo last year, Meta said the political tumult in the United States would distract critics from the feature’s release.

© Lucia Vazquez for The New York Times

As Iranian authorities restore some online services after crushing antigovernment demonstrations, they are using a technological dragnet to target attendees of the protests.

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Agents use facial recognition, social media monitoring and other tech tools not only to identify undocumented immigrants but also to track protesters, current and former officials said.

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Facial recognition at security and immigration checkpoints and gates could ease airport hassles, even as the technology raises privacy concerns.

© Tim Cook