Uwug Ltd & Another v Ball (t/a Red) [2014] EWHC 4019 (IPEC) is a decision of Judge Richard Hacon in the IP Enterprise Court for England and Wales on 9 December 2014. The action concerned infringement of UK registered and unregistered designs for what, the court explained, was a metal frame which supports a leather sling used for bondage sexual activities.

Having earlier established that the design rights, it fell to the court to pronounce on the basis upon which damages should be awarded. Of the various heads under which the design right holders claimed damages, the only one allowed by the court was the "user principle".  For the avoidance of doubt, "user" in this context is not the user of the infringing product itself but the unlicensed user of the design rights in question. In this instance, the sum which the infringer was assessed as having to pay if he were licensed to use the rights was 10% of the sale price of his products.