Kids can be cruel - we all know that.
Most adults these days will be able to relate to some form of bullying during their time at school, whether it was the kid at primary school who no longer wanted to be their friend to the physical dustup in the playground as they got older.
If they didn't experience it - either as the bully or the bullied - chances are they saw it going on or knew it was happening.
When I was a teen, it was still the early days of the internet.
Chat rooms existed, but were in their infancy, and it wasn't until I was halfway through high school that texting came about.