In the aftermath of the fatal mass shootings in Colorado Springs, CO, and San Bernardino, CA, questions of gun control are once again at the forefront of American political discussion, and now even nonpolitical figures are weighing in.A video campaign released today by Everytown for Gun Safety is asking people to speak up against gun violence. The minute-and-a-half video clip intersperses celebrities, shooting-attack survivors, and concerned citizens, sharing among them the phrase “We can end gun violence” over an inspiring soundtrack.Julianne Moore, Amy Schumer, Jennifer Aniston, Michael J. Fox, Sofia Vergara, and Kristen Schaal are only some of the celebrities who have chosen to lend their voices to the cause. At the end of the clip, the organization invites its allies to record themselves saying the same phrase and add their own voice to the video.Schumer vowed to advocate for firearm-law changes after two women were killed this summer at a showing of Schumer's movie Trainwreck.What’s perhaps saddest about the PSA is that even though it’s a response to those most recent gun-violence attacks, it’s connected to another tragedy, as well. This coming Monday will be the third anniversary of the Sandy Hook mass shooting in Newtown, CT , which killed 26 people, most of them young children.