Cyber Monday ... expected to be the biggest online shopping day of the year.

Cyber Monday ... expected to be the biggest online shopping day of the year. Photo: Getty Images/AFP

US Federal law enforcement authorities have seized 132 domain names in several countries to stop them from selling counterfeit merchandise online.

The Cyber Monday crackdown comes on what's expected to be the biggest online shopping day of the year. US Immigration and Customs Enforcement's Homeland Security Investigations co-ordinated the effort with Europol and police in Belgium, Denmark, France, Romania and the United Kingdom.

Authorities say it's the third consecutive Cyber Monday that websites selling knock-off sports jerseys, DVDs and other goods have been targeted.

They say sites were seized after copyright holders confirmed that products purchased there by investigators were illegal.

Site visitors now see a banner explaining the seizure and copyright infringement.

Homeland Security field offices in New York, New Jersey, California, Maryland, Colorado and Texas investigated.

AP