They're not owned by the federal government, but they do get a lot of federal government money.
> The National Center for Missing & Exploited Children® was established in 1984 as a private, nonprofit 501(c)(3) organization. Today, NCMEC performs the following 15 specific programs of work, funded in part by federal grants (34 U.S.C. § 11293): Source: https://www.missingkids.org/footer/about
US DOJ OJJDP lists recent grants totaling $84,446,366 in FY19 and FY20. Source: https://ojjdp.ojp.gov/funding/awards/list?awardee=NATIONAL%2...