More than 2,000 web shops selling fake or non-existent goods have been shut down by police.
Goods purportedly from GHD, Ugg, Tiffany and Nike had been peddled by the sites, said the Metropolitan Police E-Crime Unit.
It said shoppers had been tempted by low prices.
The unit warned that the goods supplied were counterfeit, adding that many sites had taken payment and then not despatched any products in return.
It said many of the sites had been simply set up by cyber thieves to harvest credit card and banking details.
Police officers worked with domain registrars to identify the rogue traders and then used Nominet's powers to seize and shut down the offending domains.
Detective Inspector Paul Hoare from the E-Crime Unit said many gangs registered sites in bulk solely to dupe customers. He said the campaign to close the criminal sites would continue in the run-up to Christmas.
"I would urge customers to take all precautions to ensure they buy from legitimate sites only," he said.
DI Hoare said consumers should check a website's credentials to ensure it was approved and reputable. He said they should also consider using a credit card for payments over £100 and perhaps reserve one card for online shopping.
DI Hoare said shoppers should also be wary of unsolicited offers that arrive via email.
The E-Crime Unit took similar action in 2010 when it shut down about 1,800 sites.