The case of Lego® is an interesting example. Godtfred Kirk Christiansen had invented these special clamping building blocks together with his father Ole Kirk Christiansen and applied for a patent in 1958. As long as the patents were in force, nobody was allowed to sell compatible building blocks. As the basic patents expired, the company had to come up with new strategies to defend its market leading position. As we all know, Lego® developed new brick shapes and began to create Lego® worlds. Lego® figurines started populating the world and electronic components debuted. The miniature worlds are scaled up and brought to life at Legoland®, a leisure and holiday park. Behind the scenes, the Danish company has continuously registered new brands. In the Swiss trademark register, for example, over 60 Lego® trademarks can be found. The new block shapes have been protected by designs, as exemplified by the German Design Register, which today contains 63 entries for Lego® toys. In the 1990s, when the category of shape trademarks was created, Lego® registered the brick as a shaped trademark. These marks were used against competitors which led to influential supremecourt decisions. Read on and find out what legal means are available to defend against imitators.