In the Greenville, Ky., high school, Friends of NRA raffled off semiautomatic rifles and handguns, guns with high-capacity magazines and pump-action shotguns. The NRA Foundation’s fundraising program had displayed guns in the gym in the past, but this time organizers showed only pictures, bowing to objections from parents who pointed to a shooting at another western Kentucky high school last year that left two students dead and more than a dozen wounded. Pockets of resistance to Friends of NRA events are cropping up across the U.S. as mass shootings become more frequent, the Washington Post reports. Although National Rifle Association officials say only a small fraction of raffles are held in schools, opponents have pressured other venues to stop hosting the fundraisers. The events netted more than $33 million last year.

That money is the leading source of cash for the NRA Foundation, a charity that supports shooting sports. The events combine the efforts of what organizers say are 13,000 volunteers with the NRA’s multimillion-dollar marketing machine. They are family-focused by design, helping to cultivate the next generation of gun owners and NRA members. In a 2013 video posted to the Kentucky chapter’s Facebook page, a narrator calls the group “the NRA’s best-kept secret.” Friends of NRA boasts that its events feature the “latest and greatest” guns thanks to “amazing relationships with all the top firearms manufacturers.” The foundation gives half the money it raises to shooting and archery teams, 4-H clubs, Scouting troops and other youth groups, the NRA says. It uses the other half for national firearms educational programs. A deadly high school shooting last year 80 miles from Greenville galvanized a vocal minority in the conservative-leaning community. Opposition to Friends of NRA has emerged in areas scarred by mass shootings and neighborhoods that have long favored gun control.