Google has apologised after finding a bug which meant some people's private videos were shared with others by mistake.
The bug affected Google Takeout, which enables Google Photo users to export the content of their accounts, for four days, between 21 and 25 November 2019.
Google said those who used it may have either received an incomplete archive, or some videos which were not theirs.
It declined to say how many accounts were involved.
However, a spokesman told the BBC it was "less than 0.01%" - or 100,000 - of Google Photo's one billion users.
The issue only affected video, not photos or any other data.
"We fixed the underlying issue and have conducted an in-depth analysis to help prevent this from ever happening again. We are very sorry this happened," the firm said in a statement.
In its notification to those affected, Google recommends deleting the data export and carrying it out again.
"It is very worrying that other people may receive your private videos with all the implications for your privacy and possibly safety and those of others," commented Pat Walshe, managing director of Privacy Matters.