OK lizards, I looked it up:

[CITE: 18USC373]

TITLE 18—CRIMES AND CRIMINAL PROCEDURE

PART I—CRIMES

CHAPTER 19—CONSPIRACY

Sec. 373. Solicitation to commit a crime of violence

(a) Whoever, with intent that another person engage in conduct
constituting a felony that has as an element the use, attempted use, or
threatened use of physical force against property or against the person
of another in violation of the laws of the United States, and under
circumstances strongly corroborative of that intent, solicits, commands,
induces, or otherwise endeavors to persuade such other person to engage
in such conduct, shall be imprisoned not more than one-half the maximum
term of imprisonment or (notwithstanding section 3571) fined not more
than one-half of the maximum fine prescribed for the punishment of the
crime solicited, or both; or if the crime solicited is punishable by
life imprisonment or death, shall be imprisoned for not more than twenty
years.

Now, If a person hands you a Koran, in which it says “Kill Infidels”; and he says or implies that the Koran is the word of G-d, and is to be followed, isn’t he violating this US law?