The 14th amendment overrides the 1st in this case. You CAN be prosecuted for providing aid or comfort to an insurrection, even just verbal support (or, providing hosting services.)
To clarify slightly: Some supreme court cases have settled that speech can be a form of engaging in "insurrection or rebellion"
based (presumably, but I'm not a constitutional scholar) on the 14th amendment's section 3:
No person shall be a Senator or Representative in Congress, or elector of President and Vice-President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof. But Congress may by a vote of two-thirds of each House, remove such disability.
