Automated facial recognition and image correlation has been widespread and used on photos on the internet for a decade at least now.
In my experience it's usually the small to medium companies that don't care about stuff like if it's actually legal or not, and it's not like it's hard to do - [https://pimeyes.com/en] is one of a great many.
That said, if a hiring manager looks it up, and passes instead of hires and doesn't tell anyone why, it's not like that would show up in a database or procedure somewhere.