tournament since 1982. It was held in Toronto and was attended by 83 participants. The tournament led to the formation of the World Cube Association in 2004. Annual sales of Rubik branded cubes were said to have reached 15 million worldwide in 2008. Part of the new appeal was ascribed to the advent of Internet video sites, such as YouTube, which allowed fans to share their solving strategies. Following the expiration of Rubik's patent in 2000, other brands of cubes appeared, especially from Chinese companies. Many of these Chinese branded cubes have been engineered for speed and are favoured by speedcubers. On 27 October 2020, Spin Master said it will pay $50 million to buy the Rubik's Cube brand. Imitations Taking advantage of an initial shortage of cubes, many imitations and variations appeared, many of which may have violated one or more patents. In 2000 the patents expired, and since then, many Chinese companies have produced copies of, modifications and improvements upon the Rubik and V-Cube designs. Patent history Nichols assigned his patent to his employer Moleculon Research Corp., which sued Ideal in 1982. In 1984, Ideal lost the patent infringement suit and appealed. In 1986, the appeals court affirmed the judgment that Rubik's 2×2×2 Pocket Cube infringed Nichols's patent, but overturned the judgment on Rubik's 3×3×3 Cube. Even while Rubik's patent application was being processed, Terutoshi Ishigi, a self-taught engineer and ironworks owner near Tokyo, filed for a Japanese patent for a nearly identical mechanism, which was granted in 1976 (Japanese patent publication JP55-008192). Until 1999, when an amended Japanese patent law was enforced, Japan's patent office granted Japanese patents for non-disclosed technology within Japan without requiring worldwide novelty. Hence, Ishigi's patent is generally accepted as an independent reinvention at that time. Rubik applied for more patents in 1980, including another Hungarian patent on 28 October. In the United States, Rubik was granted on 29 March 1983, for the Cube. This patent expired in 2000. Trademarks Rubik's Brand Ltd. also holds the registered trademarks for the word "Rubik" and "Rubik's" and for the 2D and 3D visualisations of the puzzle. The trademarks have been upheld by a ruling of the General Court of the European Union on 25 November 2014 in a successful defence against a German toy manufacturer seeking to invalidate them. However, European toy manufacturers are allowed to create differently shaped puzzles that have a similar rotating