If there's a history of such speech inciting imminent lawless action, then can't we say that such speech incites imminent lawless action? So if you have a foru

If there's a history of such speech inciting imminent lawless action, then can't we say that such speech incites imminent lawless action? So if you have a forum, where certain kinds of statements on that forum usually/often cause very quick lawless action, can't you say that such statements on that forum are not constitutionally protected free speech? Or is that not a valid application of Brandenburg?