In the United States, the legal doctrine of separation of church and state requires that government-funded activities not be religious in nature, in order to preserve separation of church and state. This includes public schools, which are not allowed to call for or conduct prayer or other religious activities (though ironically, as far as I know they still do include the relatively-new "under God" in the Pledge of Allegiance, and this is seldom if ever questioned).
This apparently bothers many religiously-oriented people, for reasons which are not entirely clear.
There is a myth, widely propagated by leaders of the religious right, that even individual religious expression (such as prayer) by students is forbidden; this is often described in inflammatory terms such as "kicking God out of the schools".
This misperception has been reinforced by a number of incidents in which school officials, for reasons which remain unclear, did in fact attempt to suppress such expression. The courts have almost always ruled in favor of the individual's freedom to religious expression.
Another myth is that the American Civil Liberties Union (ACLU) has been complicit in these attempts, defending the school rather than the individual freedom of expression; in fact, the ACLU have many times defended freedom of religious expression, including that of Christians, Muslims, and other religious groups.
- Prayer in US public schools is often an issue because it is heavily promoted by the religious right but conflicts with the separation of church and state required by the US Constitution (a fact often denied by the promoters).
- The Sneeze (internet chain mail) purports to be a true story in which students were forbidden from expressing religious sentiment.
- Snopes verifies that an appeals court ruled that teacher-led recitation of the Pledge of Allegiance in public schools is unconstitutional.