Whoever incites, sets on foot, assists, or engages in any rebellion or insurrection against the authority of the United States or the laws thereof, or gives aid or comfort thereto, shall be fined under this title or imprisoned not more than ten years, or both; and shall be incapable of holding any office under the United States.
That reading of the law is frankly stupid. They are organising a protest and AWS isn't able to take on the responsibility of being the moderation team for an entire internet. And not every nasty comment on the internet represents a threat requiring a police response.
There isn't any rebellion or insurrection going on, these are protests. We all know what a US political protest looks like, we've been watching them for years. There isn't anything especially new here.
18 U.S. Code § 2383 - Rebellion or insurrection
Whoever incites, sets on foot, assists, or engages in any rebellion or insurrection against the authority of the United States or the laws thereof, or gives aid or comfort thereto, shall be fined under this title or imprisoned not more than ten years, or both; and shall be incapable of holding any office under the United States.