And now that post that I put-up has been taken down. Very interesting!!!
Actually, since the post contained a terroristic threat, that moreover constituted a true threat under prevailing jurisprudence in any of the Court of Appeals circuits*, X did the right thing in taking it down. It would also have been appropriate to report the poster to law enforcement.
* What constitutes a true threat varies. All the appellate courts agree the person making the threat must have the means to carry it out (which as the threat was to buy a gun to commit violence would simply mean having enough money to buy the weapon), but differ on whether it must be judged to be an actual threat by a reasonable hearer to whom it was addressed (in this case any white man), or by a reasonable third party hearing the threatening speech who was not the party threatened, rather than a joke or hyperbole.