Thank you for all the answers.
I might, of course, have been overreacting as it is the overall opinion here. As Grant says, it was not confrontational in any way.
"If it had been a random citizen asking you the same thing, would you still be insulted?" Streetcar asks. No, I wouldn’t.
The difference is that a cop in a uniform is an “official” person and in our society he, as a principal rule, is not supposed to talk to citizens unless he has observed something illegal or he is investigating a committed crime. I guess that in your countries the police may have other rights.
Recently we have experienced increasing violence and the usage of knives and guns in Denmark. Here new rules established by the Minister of Justice specifically allow the police within certain well defined areas of Copenhagen and for a limited time on a random basis to investigate and check if people are carrying knives and other weapons. It is no longer permitted to carry knives with a blade exceeding a few inch unless you are a scout. The possessing and wearing of guns is and has always been strictly forbidden. But outside these neighborhoods cops cannot without reasonable suspicion check if people are breaking the law. In neighborhoods where drug dealers operate the police cannot legally check position of drugs unless they observe something unusual.

That is why I being - and with my camera around my neck looking like - a tourist feel offended when a policeman stops his car and is telling me that wearing a kilt is uncommon.

Greg

www.dress2kilt.eu