This is analogous to alleging a company is complicit in an MS13 murder committed by an illegal immigrant, because the company wasn't strict enough in checking the immigration status of their employees. Or, ignoring sovereign immunity, alleging permissive immigration policy and lax border enforcement render the state culpable for crimes committed by immigrants, legal or illegal, that would otherwise not be in the country in the first place.

It's significantly curtailing freedom, mostly of innocents, for the sake of alleged safety. One is freedom of movement, the other of speech.

Presumably the family petitioning the Supreme Court wouldn't ask the US to sacrifice immigration for the (alleged) sake of a handful of murders, so what makes freedom of speech a more legitimate sacrifice?