Against the background of the European Union summits in Gothenburg, Sweden in 2001 and Copenhagen, Denmark in 2002, this article investigates the legal framing of police public order practices in conjunction with mass demonstrations and rioting in urban surroundings. Differences between legalistic and opportunistic ways of administering laws and regulations are illustrated, focusing on the policing of political disorder in two case studies with quite different outcomes. Theoretically, attention is also directed towards the notion of crisis, in terms of frustration and aggression. The basic argument is that the hyper-complexity of the legal framing in Sweden seems to have played an important, but unintended, role in the violent handling of the serious riots in Gothenburg; and that the legal powers in Denmark, in contrast, seems to have contributed to the less aggressive handling of the protest events during the European Union summit in Copenhagen.