We can call them u.f.o.'s because that's what the acronym stands for. They didn't know what they were but chose to release the film regardless. I don't see mass panics and gov't people being asked to answer for the same. I see the general public as more reasonable than we give ourselves credit for. Are you going to quit your job because suddenly an alien is in town. Sure, some people may freak but I don't see the majority all of a sudden in mass panic. No rockets have come raining down on us from space yet and if they do, well than I guess we'd be in trouble then.
I don't know Elizabeth. We all would require the basics still: food, water etc.. Our sights would likely be set higher and things would begin to change over time but anarchy, who knows?