Do you realize that most of humanity would be completely worthless in the event of something inexplicable happening? Think of all the panic on 9/11. It was clear pretty early on that it was a terrorist attack, and thus within the bounds of human expectation. Now imagine something nobody knew how to explain. Something that cannot you cannot blame on the terrorists, something that goes beyond anything ever recorded in human history. Humanity would soil its collective pants, then probably all get addicted to crack or something.

In a zombie-apocalypse scenario
Many, if not most Americans would hole up in their homes waiting for the government to effect a rescue plan of some sort. Since most homes are not built to keep out hordes of brain seekers (whatever the movies say) it would only be a matter of a few hours before their brains were consumed. The military would probably be as freaked out as everybody else and most soldiers, I predict, would desert. Law enforcement would be useless, most of them either blowing their own brains out, getting high on confiscated drugs, or going home to protect their families. Elsewhere, where zombies are not a part of the popular culture pretty much everybody would be eaten long before they figured out what was going on. In both cases the surviving stragglers would probably end up committing suicide.

Flying saucer crash-landing in Times Square live on CNN
Thousands would die in the immediate migration of rubberneckers from all over planet Earth to the site of the crash-landing. Then, should the aliens prove hostile, thousands more would die in the mass flight. During all this everything might be publicized on CNN, provided the journalists didn’t lose their heads, there is no guarantee to this. Everybody who didn’t drive, fly, or walk to New York City, would be watching 24 hours a day so nothing would get done, America’s infrastructure would grind to a halt. There would be mass power outages, water shortages, which would add to the panic about an alien invasion and the destruction of mankind. Every whackjob and sci-fi nut would become the equivalent of a priest, and there would be religious wars as people struggled to explain and come to terms with this.

Women suddenly turn into rabid, man-raping nympho-predators
Your dream and mine coming true. Until your dick is chafed and your back is sore, the inside of your mouth is coated with pubic hair, you have infected fingernail scratches all over your back, and the 40 or 50 women crammed in your apartment and jostling for their turn still want more. They would take to shoving Viagra pills down your throat. When it stopped being fun, you would feel like you were being used by predators, and you would have all the issues that rape-victims face. Basically men would become malnourished, and die of exhaustion and/or dehydration.