I've done the math, and I feel the probability is approaching 100% that we're not alone in the Universe. Whether we've already been visited or not I'll leave up to your own opinions, however, at times like this I can't help but wonder what the hell people would do if we DID get visited (a huge "We're here!" that's so big that governments can't cover it up).
I mean, if we can't even seem to get along within our own species, what will happen if entities that are not genetically related to us suddenly arrive?