“300K missing children!!” is fake news. At least they’ve moved on from RFK claiming that HHS was participating in human trafficking though.
The number stems from this report, which simply says that 291K had not been served a notice to appear. That doesn’t mean they’re missing.
https://www.oig.dhs.gov/sites/default/files/assets/2024-08/OIG-24-46-Aug24.pdf
This report from March 2025 confirms that for one, as of January the number was down from 291K to 233K. And also confirms there is a “backlog” in issuing notices to appear, so it’s because they simply haven’t issued them, not because they issued them but couldn’t find the children.
https://www.oig.dhs.gov/sites/default/files/assets/2025-03/OIG-25-21-Mar25.pdf