While America has earned a reputation for litigiousness, it's Canada that's been the recent battleground for an interesting industrial design copyright violation lawsuit. We'll try to cut through the legalese to explain:
In 2003, Swiss kitchenware manufacturer Bodum designed a line of drinking glasses. They featured a double-walled design, which provides insulation on account of the vacuum between the walls. Bodum put the glasses on the Canadian market in late 2003, and registered the designs under Canada's Industrial Design Act in mid-2004.
In 2006, Canadian kitchenware manufacturer Trudeau released their own double-walled glass design. To my eye the form of Trudeau's glasses are no dead-ringer for Bodum's, but that wasn't Bodum's issue: They claimed they had copyrighted the double-walled insulating feature, and filed suit against Trudeau in early 2007.
It took until this year for the trial to come to a conclusion, following years of legal negotiating. In a double blow to Bodum, the court ruled in favor of Trudeau, stating that 1.) Trudeau's designs didn't infringe upon Bodum's, as the forms of the glasses were significantly different enough (based on the minor detail of the profiles of each design ending in concavity versus convexity, up at the top), and 2.) Bodum's ID registrations were invalid in the first place. This seems murky to me, but apparently you can not copyright that insulating function:
Section 2 of the Industrial Design Act defines a "design" as being the "features of shape, configuration, pattern, ornament and any combination of those features that, in a finished article, appeal to and are judged solely by the eye." Justice Boivin began his infringement analysis by reaffirming that industrial designs do not confer a monopoly over functional elements, and as such, the similarities in utilitarian function between two products are not to be considered by the court in an infringement analysis.
Any of you who care to wade through the entire legal transcript (translated into English, as the trial was conducted in French) can find it here.