India has been killing off girls at high rates for a generation. Sex-selection abortions have produced ratios of 120 boys to 100 girls born in some rural provinces. There are already millions of young men in India with no reasonable hope of marriage.
The world heard the horrible story of the gang rape and murder of a woman in Delhi in 2012. This month a Swiss woman was gang-raped in central India. In each case the woman was with a man, who the gang beat and subdued before raping the woman in front of him.
Two cases does not make a social trend. Still, these cases, in the larger context of masses of poor, unmarriageable men, suggests to me a story that makes sense. Gang rape is extremely rare - almost all rapes, even stranger rapes, are by lone men who hide their deeds from everyone. To get a whole gang of men in a condition to rape a woman together, and in front of one another, takes unusual circumstances. And the circumstances of seeing a young woman having fun with a man seems to me the very circumstance that would madden a gang of permanent bachelors the most.
The killing off of girls, mostly by sex-selection abortion, is a great evil in the world. China, India, Eastern Europe, and the Arab countries are the worst offenders. I think they will reap the whirlwind. A rising rate of gang rapes is one the forms of that whirlwind that I think likely.