Consider that (at an extreme) using the military to repel an armed invasion is most definitely a matter of national security. The authoritarian and the libertarian can both claim "national security" and mean very different things in practice.

Ensuring a robust judicial process and having precise definitions for such terminology are both serious issues here. The police are literally supposed to protect the children (and the adults!), but "protecting the children" is hardly desirable.

Edit:

> (A bit unsettled we now live in an era of "It's illegal to download <app to watch cat videos>," even if the national security concerns were true.)

I'm certainly no fan of the current administration, but how is a centralized and widely used social media app not a potential national security threat? For any country, it seems highly concerning to me for either the employees or infrastructure for such an app to be located in any jurisdiction that isn't a close ally. As an example, consider the destabilizing influence that Google could potentially exert by intentionally skewing search results for a specific topic in a calculated and subtle manner.

Honestly I'm somewhat surprised that the EU hasn't objected to Facebook or Twitter on these grounds. I suppose they mostly trust us not to meddle in their elections (and us them for that matter).