It's an ongoing concern. Some of the things we saw in the Central African Republic were particularly egregious in these terms, with a number of the contributors there.
The acid point here always comes back to the fact that the UN itself doesn't really have either the legal authority or the operational capacity to prosecute soldiers who engage in this behaviour or commanders who allow it. That has to come back to host nations. Canada could demonstrate leadership, if it encounters an issue like this, by engaging in the correct forms of accountability of its own troops.