The internet provides a media that is easily accessed by children who may not understand what they are viewing. By indoctrinating children with these ideas in their most understanding and accepting phase of their lives, these groups are able to quite easily make followers for life out of these children.
Children are the future of hate groups.
Hate is not an intrinsic human behavior. Without children being conditioned to hate, there would be no hate groups because these children would grow up in a world where they didn't find any reason to hate people who were different than they were. Unfortunately, we live in a world surrounded by hate. Most people try to shelter our children from the horrors of hate, but there are others who try their best to advocate hate. Member of hate groups believe that everyone should believe the same way that they do.