That is true, but I just don't think that should be the thing that stops people from doing shitty things.
Think of it this way, a hypothetical:
I think it's bullshit that grocery stores are profiteering off supply chain issues.
I feel justified in stealing some groceries this time through.
I am also aware of the consequences of stealing the groceries because it's common knowledge.
Therefore, I am going to pay for the groceries even though I feel justified in stealing them, because I do not want to suffer the consequences of stealing the groceries.
Even though I technically know that stealing the groceries is wrong (because stealing is considered immoral) it's not the fact that it's wrong that's stopping me from doing it.
Obviously this is a very simply example that does not match the severity of what we're discussing here, but the point stands. These kids knew what they were doing was wrong, it's common knowledge and they chose not to care because they either were not aware of the consequences of their actions
or they were aware and disregarded them.
Judging by that text exchange, it seems likely to be the latter.