A coalition of anti-gay groups is once again urging parents to keep their children out of school on the annual anti-bullying “Day of Silence.” The Illinois Family Institute published the call to action on its website today, signed by activists including Matt Barber, Concerned Women for America’s Penny Nance, Americans For Truth About Homosexuality’s Peter LaBarbera, Scott Lively, Linda Harvey, Liberty Counsel’s Mat Staver, and MassResistance’s Brian Camenker.

Calling the GLSEN-sponsored event “the queen of all the numerous homosexuality-affirming activities that take place in public schools,” the activists allege that it is meant to “indoctrinate 16-year-olds.”

“We must demonstrate the boldness and perseverance of the Left if we hope to stop the relentless appropriation of public education for the promotion of homosexuality,” they exhort.

The Day of Silence has long been a target of anti-gay group’ efforts to crack down on anti-bullying efforts in schools.