This has/is already happening, how do you think they found a 15 year old post where Graham Platner was dancing with his shirt off that got like 15 views? How do you think they found his "anonymous" reddit account?
Yeah, I agree, there's a file on everyone. However, actions like this may backfire. In this case I think this will help Graham Platner rather than hurt him
These days a Nazi tattoo can make you very popular with 50% of the population.