A new coalition of celebrities and activists, including actor Alyssa Milano and Parkland student David Hogg, announced plans Friday to take on the National Rifle Association and elected officials who accept money from the powerful gun advocacy group.

In an open letter to NRA Executive Vice President Wayne LaPierre, which was first obtained by TIME, the more than 100 members of the newly formed NoRA Initiative — short for No Rifle Association — pledge to reduce the NRA’s influence in American politics through a series of voter registration drives, nationwide art campaigns, demonstrations and boycotts.

“Your time signing checks in our blood is up,” the letter says. “We’re coming for your money. We’re coming for your puppets. And we’re going to win.”

NoRA launched its initiative Friday, on the 19th anniversary of the mass shooting at Columbine High School, as students across the country participated in a national school walkout in part to commemorate the 1999 massacre.

NoRA’s members include Jimmy Kimmel, Amy Schumer, Alec Baldwin, Ashley Judd, Julianne Moore, Patton Oswalt, Constance Wu, W. Kamau Bell, Amber Tamblyn, Debra Messing, Minnie Driver, Tarana Burke, as well as several artists, policy experts and survivors of gun violence. They say their goal is expose public servants who have been stymying gun control legislation after taking money from the NRA. NoRA believes it can use grassroots and digital awareness campaigns to help vote those legislators out of office.

Milano, who helped popularize the #MeToo movement last year, said she was moved to help form the new NoRA initiative one day after 17 Marjory Stoneman Douglas High School students and faculty members were gunned down at the Parkland, Fla. school on Feb. 14. The impassioned student response to that shooting spurred a national debate on gun violence and reinvigorated calls for new gun control laws.

“I am the mother of two children,” Milano told TIME. “To see what’s going on in this country as far as gun violence, and the lack of real fortitude to do anything about it, is keeping me up at night.”

Milano reached out to dozens of gun control activists and friends, and the concept for NoRA began to take shape. The actor said she was inspired by the Parkland students, who were named to the 2018 TIME 100 list of the most influential people in the world. “To see these Parkland kids doing what they’re doing, to get up there, to be so brave, to be so open and really take the initiative to try to fix this is great,” Milano said, “but they need support.”

The members of NoRA expressed outrage at the NRA’s influence, particularly during the 2016 election cycle. The gun advocacy group poured more than $54 million on outside spending during the 2016 elections, according to the Center for Responsive Politics. Significant sums went to President Donald Trump, who was a vocal supporter of the NRA during his campaign.

The NRA did not immediately respond to a request for comment about NoRA.

Read More: Here’s How Much the NRA Has Given to Florida Lawmakers

“After five years of pushing for changes around gun laws and trying to hold the NRA accountable, nothing has been done,” said Po Murray, chair of the Newtown Action Alliance, which is one of the groups managing NoRA’s funds. “The time is now to end the NRA’s powerful influence in politics.”

NoRA runs on private donations and has raised more than $25,000 since February, according to Milano.

She says the group has “surprises up our sleeves,” including for events timed to the NRA’s annual convention in Dallas May 3-6. “When like-minded people come together for the common good and for a cause they believe in,” Milano said, “they can move mountains.”

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