  We argue that cosmic censorship is violated in the collision of two black
holes in high spacetime dimension D when the initial total angular momentum is
sufficiently large. The two black holes merge and form an unstable bar-like
horizon, which grows a neck in its middle that pinches down with diverging
curvature. When D is large, the emission of gravitational radiation is strongly
suppressed and cannot spin down the system to a stable rotating black hole
before the neck grows. The phenomenon is demonstrated using simple numerical
simulations of the effective theory in the 1/D expansion. We propose that, even
though cosmic censorship is violated, the loss of predictability is small
independently of D.
