He told me that the Sodom and Gomorrah story is about hospitality law and not homosexuality.
This is supported by Ezekiel chapter 16:
Behold, this was the guilt of your sister Sodom: she and her daughters had pride, excess of food, and prosperous ease, but did not aid the poor and needy. They were haughty and did an abomination before me.
The men of Sodom were certainly sodomites, but that's not why their city burned.
but college students are some of the most strongly connected people around. They are more likely to be friends with their neighbors (who all share their age and occupation), Facebook adoption rates in their social circle are very high, and they have a very strong overlap between work, living arrangements and social life.
This isn't generally worrisome for the rest of us, who aren't Facebook friends with everyone on our street or office building.
No amount of careful planning will ever replace dumb luck.