Shein filed the lawsuit against Temu -- which she called one of Shein's largest e-commerce rivals -- accusing it and affiliated companies of their "brazen intellectual property infringement; blatant theft by misappropriation of trade secrets." Shein, according to the complaint filed in a District of Columbia federal court, says Temu has orchestrated widespread supplier infringements on its copyrights and trademarks as part of an effort for "an unearned and illicit foothold" into the U.S. market.

Shein sues Temu for infringement : Unfair Competition Charges

Temu has been accused in the lawsuit of being built on a foundation and source of counterfeit goods, trade secret thefts, patent violences. Instead, Shein maintains that Temu is not simply a marketplace and has authority over the activities of its sellers — deciding what they can list and at which price points. Temu trains suppliers to "copy and imitate" Shein designs and bars them removing infringing products from the platform, too--even after admitting they infringed.

According to Shein, Temu has used deceptive tactics by manufacturing phony social media accounts and persuading influencers both in their employ and elsewhere they have recruited to instead market knockoffs of Tenu's items as cheaper — higher quality than what can be found on the site.

Trade Secrets and Counterfeit

It states that Temu managed to steal Shein's bestseller data and then shared it with hundreds of people in order to take the first place. The information he shared with suppliers was said to have included trade secrets about how Shein's fashion designs were made, allowing third-party manufacturers to copy them and allegedly commit intellectual property theft. The complaint also alleges that Temu infringed Shein's copyrights by using images of authentic Shein products to advertise counterfeit goods for sale on its site.

Overall, Shein's lawsuit alleges 16 different causes of action against Temu ranging from copyright infringement to false advertising and trademark counterfeiting all the way down to unfair competition. Shein is asking for damages, injunctive relief and its attorney fees.

Ongoing Legal Battles

That lawsuit is part of a broader legal battle between the fast-fashion rivals. In response to the suit, Temu shot back that such legal action was hypocritical given Shein has also been on other end of IP lawsuit. A rep for Temu said in a statement, "The gall is astounding... Shein — which is drowning under an avalanche of IP lawsuits against them — has the audacity to invent claims like this about someone they get sued over and over again doing what's alleged here."

Earlier in December, Temu had filed its own IP claims against Shein for intimidating its sellers and misappropriating proprietary business information. Each of the companies is also facing antitrust complaints in Massachusetts and regulatory scrutiny elsewhere.