Don't Suppress Them
There's a reasonable element of objectivity to the existing law. "Directing, advising, and encouraging" are activities that probably can be pinned down to specific individuals and maybe even organizations. But SB 189 gets cloudy when it considers "boosting" to be an activity that can occur through "an employee, agent, or subsidiary." It opens a can of rhetorical worms that will no doubt be tested in the courts. Consider that in 2017, the Sierra Club announced that it was supporting Native American resistors of an oil pipeline crossing eastern Oklahoma. If similar protests in South Dakota were supported by the organization and the protests turned violent and destructive, would the new law apply? I'm certain the Sierra Club neither openly nor covertly supports violence, but if its sponsored demonstrations get out of control would the club be considered a "booster" of the mayhem? Would the Sierra Club be considered an "agent" of its financial supporters, putting them in legal jeopardy?
As compelling as these questions are, the larger point is how chilling an effect a law like this will have on those who legally demonstrate. True to its intent, SB 189 will probably give potential activists second thoughts about gathering at protest sites, where passions can easily get out of control and, even if they don't, some incidental crowd management and damage repair expenses are likely to accrue. Who pays for those? As with its other question-raising elements, this dissent-stifling law is unclear and imprecise.