Or society could move on and accept that people progress. Also I am not aware of any instances where 30 year olds were punished for a racist joke they made with 13.
The only instance I remotely know, is of a german politician, who made a deeply racist and neonazi pamphlet when he was 17 - and the result was some public outcry but nothing else.
Still privacy is important, simply because those who do surveillance are not trustworthy either.
Aside from getting her fired from her job, they also tried to destroy her dad's business.
I get that less-than-10 years isn't a ton of time, but it also represented nearly half her life. People tend to grow up a lot in their teens even if it's still common for there to be some immaturity leftover in their early 20's
Lynch mobs usually ain't fair or just or busy with factfinding, but I know there are also a lot of people hiding behind a mask and do not like to get exposed by confronting them with something out of a time when they were not so careful yet.
Personally I just avoid racists (or argue with them) and don't attack their stuff or even family and don't think this is the way, to get to a world without or even less racism.