Since the aclu has been working against us for the past 25 years, I find anything they say as suspect, that is, there must be an ulterior motive.
But if you read the fine print, the ACLU admits that it used the default match settings that Amazon sets for Rekognition, which is an 80% confidence level. Amazon reran the study with 30 times as many mug shots and the 99% confidence threshold they recommend for law enforcement use and the misidentification rate dropped to zero. You probably missed the medias retractions.
Have No Fear of Facial Recognition
https://www.wsj.com/articles/have-no-fear-of-facial-recognition-11564955494