PASCAGOULA, Mississippi -- The Wisconsin-based Freedom From Religion Foundation has issued a warning to Mississippi's 151 school superintendents regarding prayers before tonight's season-opening high school football games, according to several news organizations and social media sites.

Last September, the Freedom From Religion Foundation challenged the Jackson County School District's use of prayer at school-sponsored events, and since then, the district has been looking into a policy to protect student speech.

The Wisconsin-based foundation cited a 2000 U.S. Supreme Court case involving Santa Fe schools in which judges ruled that a policy permitting student-led and student-initiated prayer at public high school football games and other public school-sponsored events violates the establishment clause of the First Amendment.

The Mississippi House passed the Schoolchildren's Religious Liberties Act, which addresses some of the same issues Jackson County schools are facing.

House Bill 638, which passed on a 92-25 vote, says each school district shall treat a student's voluntary expression of a religious viewpoint in the same manner it treats their expression of a secular viewpoint.

Students must be allowed to organize prayer groups, religious clubs and other religious gatherings, and districts must adopt policies that establish limited public forums for student speakers at school events.

Facebook posts this afternoon showed fans organizing to have individual moments of silence before tonight's games or say the Lord's Prayer in unison.

Several school districts have announced that instead of official, school-sponsored prayer there will be a moment of silence before Friday's games.