Last month, millions of people across the world watched themselves swap places with actor Leonardo DiCaprio in the film Titanic — all it took was a photo of their face.

The Chinese app Zao went viral but soon sparked privacy concerns after users realised that they had no control over the pictures uploaded to a company specialising in image manipulation. Russia’s FaceApp, which allows users to age themselves dramatically, had raised similar fears a few weeks before.

“People seem to understand privacy risks more when a foreign country is involved,” says Adam Harvey, a technology researcher and privacy activist, pointing out that companies storing and analysing biometric data — such as facial traits, fingerprint, DNA or voice pattern — are multiplying.