Lululemon has filed a lawsuit against Costco, alleging that the wholesale retailer is selling counterfeit versions of its popular athleisure wear. The lawsuit claims that Costco's Kirkland Signature brand is offering knockoffs of several Lululemon designs at significantly lower prices. Lululemon argues that this infringes on their intellectual property and damages their brand reputation. The company is seeking damages and an injunction to halt the sale of the alleged counterfeit products. The suit highlights the ongoing challenges faced by brands in protecting their designs from being copied and sold at lower price points.