Back in July, Microsoft
claimed to have deleted its entire MS Celeb database of over 10 million images of ~100,000 individuals. The face images had been compiled on the assumption that the subjects were all public figures, but an investigation by
Financial Times journalist
Adam Harvey discovered that the database also contained images of "arguably private" individuals. Furthermore, because the images were culled from online search data, their public distribution may have run afoul of various privacy and intellectual property laws.
But because the data had been made available for public download, the database is still out there in the hands of innumerable individuals, companies and agencies.
Besides MS Celeb,
other databases have been compiled from various sources, including social media apps and games, and surveillance cameras overlooking public spaces.