This is also how most people, regardless of age, learn.
The key is - did you have to warn your son again?
I subscribe to natural consequence parenting within guardrails. People learn from experience reliably, the key is to allow manageable consequences.
The point people are making here is that your child is not on an equal playing field with the predator. The predators have an overwhelming advantage.
The issue isn’t the account getting stolen. The issue is my son giving what should be privileged information to strangers on the internet. In this case, the impact was a stolen steam account but it could easily have been much worse.