<blockquote>The Yankees began playing “God Bless America” during home games following 9/11, as did all Major League Baseball teams. While other teams stopped playing the song during every game, the Yankees continued the ritual. In an effort to promote patriotism, Yankee security officials and uniformed NYPD officers hired by the Yankees prevented fans from moving around Yankee Stadium when the song was played.

"Neither the Yankees nor the NYPD can force people to engage in acts of political loyalty," said Christopher Dunn, NYCLU associate legal director and lead counsel in the case. "As a result of our lawsuit, fans can now go to a ballgame at Yankee Stadium knowing they will not be subjected to NYPD-enforced patriotism."</blockquote>
via <a href="http://www.nyclu.org/node/2500">Yankees Settle ‘God Bless America’ Case, Won’t Restrict Spectators' Movements During Song | New York Civil Liberties Union (NYCLU) - American Civil Liberties Union of New York State</a>.