[vinalia]

If you want to create an analogy, I think chans are more like user group meetings that happen in public spaces (e.g. a public park). Nobody would kick members out of the park because they heard that they're pro-ISIS (that's just their opinion). However, display of illegal content or illegal actions would get members removed via someone calling the cops. Off topic comments that detract from the spirit of the group could also get members suspended or kicked out of the group permanently.

Is it up to park police to monitor the user groups? Sure, but they cannot take action unless it violates the law.