That elderly couple next door might look sweet, but don't make 'em angry, or you may end up spending the night with Iron Maiden.

Such was the painful lesson learned by a Stockholm couple who had the audacity to make what's being referred to as a "whistling sound" in their apartment, thus enraging their neighbors enough to engage in a little heavy metal retaliation. The Local reports that the aggrieved parties, a 71-year-old woman and her 81-year-old husband, fought back by aiming speakers at their whistling neighbors and blasting Maiden "until as late as 4 A.M."

Naturally, the police were called; according to the report, when officers arrived, they discovered "a music system on the balcony, pointed at the neighbor and playing Iron Maiden's 'Afraid to Shoot Strangers' at top volume" -- as well as "another music system in the cellar directed towards the neighbor's bedroom wall" -- all because, as the husband put it, "We wanted to give a taste of their own medicine."

Although the couple now faces harassment charges, it sounds like their campaign of metal terror may have worked; their neighbor is quoted in the report as asking, "The harassment has just carried on, I am completely broken down. How can I keep living here?"

This all sounds like the kind of thing that could have been settled over some barbecue and a few bottles of Trooper Premium Ale, if you ask us -- but we still have to commend the guilty parties for their excellent taste in revenge music.

Hear Iron Maiden's 'Afraid to Shoot Strangers'