You are probably safer in Marrakech than in most European cities.

Several years ago the Moroccan authorities set up a Tourist Brigade Police Force, whose main objective is the safety and well being of foreign tourists.  Naturally like any touristic city, there is opportunistic theft, i.e. a mobile phone or camera left on a streetside cafe table while having coffee is likely to disappear if you dont keep an eye on it. There are also a number of pickpockets - often old ladies. But in terms of safety, you should have no fears whatsoever. Even walking around late at night you are perfectly safe.

The main thing to be concerned about is crossing the roads, as there are mopeds, bikes, cars and mules all competing. With regard to mopeds, they are illegal to drive in the medina but are somehow tolerated. They are driven slalom-like at speed along narrow paths with millimetres to spare.

Visitors should also be aware of self-appointed tour guides who offer to help tourists navigate the maze of narrow streets, and then request payment for this. Some have been known to become slightly intimidating if refused a tip, but they are more of a nuisance than a danger.