It could have been a twisted commercial for an optician. A bearded Islamist points his rifle at a prisoner, shoots and misses his target. A slogan then pops up: "Need glasses?"
But it wasn't. As far as the Danish optician in question, Profil Optik, was concerned, it had simply signed a deal that included having adverts on the video-sharing site Dailymotion.com.
It – along with Nordea Bank – hadn't banked on its advert three times interrupting a 12-minute recruitment video for the the Islamic State (formerly ISIS or ISIL), which contained Islamist propaganda and footage of executions.