Teens and hate speech

I was going through my 15-year-old son's phone when I found an application called Discord. What I found on it was almost 30 message threads and servers filled with hate speech and racism. What really concerns me is that my son was taking a part in it. When I confronted him about it he mostly said that it was what all the boys at his high school say and that they didn't mean it in a hateful way. I really need some help with this one because I never thought my son could have taken part in something like this from the way I raised him. What do I do? via /r/Parenting https://ift.tt/2Mo9pkV