I found it here.
In Indiana in 2009, the senior class at a public school was asked to vote on whether to have a prayer as part of their graduation ceremony. A senior named Eric Workman, knowing full well that school-sponsored prayer is illegal even if a majority votes for it, filed a lawsuit and won an injunction against the prayer. The school administration responded by announcing it wouldn't review graduation speeches in advance, clearly hoping that some student would use the opportunity to say the same prayer -- except that the class valedictorian was Eric Workman, and he used his graduation speech to explain why the school's actions were unconstitutional and to explain the importance of the First Amendment.
Do also click on Eric Workman's name to learn more.