>>benwer+(OP)
> Such data may be useful, it says, to “identify every person who attended a protest or rally based on their smartphone location or ad-tracking records.”
"May"? This is exactly how the January 6th protestors were identified.
>>roarch+E3
I don't doubt that this technique was used for the people who stormed the capital on January 6th, but I would hesitate to describe many of them as "protestors".