I am not a moderator but I will quote the first amendment to the Constititution of the United States:
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petiton the Government for a redress of grievances."
This is purely a restriction upon the federal government (and also placed upon state governments and their representatives); this does not apply in any way to private (non-state) persons or organizations. Since this is a privately run site, the first amendment does not apply.
(You can't go into a store and yell and scream or cause, in any way, a disturbance and claim a first amendment right when you are removed; similarly, do not claim a first amendment right on this side; your first amendment rights do not apply here, as they do not apply on any other private sites.)