“This domain has been seized by ICE-Homeland Security Investigations,” the notice read. “Advertisement, distribution, transportation, receipt, and possession of child pornography constitute federal crimes that carry penalties for first time offenders of up to 30 years in federal prison, a $250,000 fine, forfeiture and restitution.”

In February this warning was posted on some 84,000 websites seized by the Department of Homeland Security (DHS) as part of Operation Protect Our Children. But only 10 of the 84,000 sites were suspected of involvement in child pornography. Instead of asking the domain host, mooo.com, to shut down the targeted sites, DHS seized the entire domain. As a result, the other 99.9 percent of the sites, mostly associated with individuals and small businesses, were spuriously linked to child pornography for three to five days.

In a terse statement emailed to some media outlets a week later, an Immigrations and Customs Enforcement official acknowledged the mistake, explaining that innocuous sites “were inadvertently seized for a period of time” but “were restored as soon as possible to normal functionality.” The official did not mention that the government had libeled the sites’ owners as child pornographers. Nor did he discuss the due process issues raised by seizing a site and taking it offline with no prior notice.

This isn’t the first time DHS has been criticized for seizing an unnecessarily wide range of websites without advance notice as part of a criminal investigation. Past cases involved suspected copyright violations rather than child porn.