There's some clear differences between FSU and Juggalos. FSU was started by a musician for the sole purpose of hurting, harming, and ridding the punk scene in Boston of skinheads, drug abusers, etc. They eventually went on to much more violent acts involving drug dealers, and broke off into many chapters in the US, all of which have purposes and goals. Juggalos are fans of ICP and other artists on their label. They're located across the globe, and originally weren't created to be violent. Some of them are involved in criminal activity, some are not, if this is the point to drive home that they're a gang, then all white men are a gang because some of us kill others and some of us rob stores at gunpoint. Some are 10 year old girls from Iowa, some are 40 year old men who own businesses in Los Angeles. FSU members exist solely for criminal activity, and are clearly exhibiting gang tendencies. Juggalos aren't. The FBI is pigeonholing an entire fan base because of the few who commit crimes. FSU is heavily involved in nothing but criminal activity.
The two posts above are speaking about modern FSU members, I was speaking about the origins of the group. Note this.