Ne Ne Ne Ne...

Ne Ne Ne Ne... is a challenge added in the Fallout: New Vegas add-on Gun Runners' Arsenal.

Obtaining
To complete this challenge, you must cripple five right arms with any form of shotgun except the Sturdy caravan shotgun; any ammo can be used but slugs (Confirmed, Xbox 360).

There are several limb types that also count towards this challenge that aren't specifically right arms, such as bloatfly right wings, radscorpion right claws, and gecko right forelimbs.

Behind the scenes
This is a reference to the film RoboCop, in which Alex Murphy was dismembered by a shotgun while Clarence Boddicker uttered a beeping noise (which sounded like 'ne ne ne ne') beforehand.