It’s time to reassemble the interocitor and send “I, for one, welcome our new alien overlords“, if I can just find the schematics. Oh, wait….
It’s too late, baby, according to Dr. Alexander L. Zaitsev’s Detection Probability of Terrestrial Radio Signals by a Hostile Super-civilization. We don’t need to worry about the dangers of actively trying to contact any extra-terrestrial civilizations — the radar signals used to study the solar system are already a million times more likely to be detected.
Some believe that they are already here, either secretly observing us or living disguised among us. Maybe they are us. Others imagine a variety of scenarios yet waiting: utopia, oppression, slavery, pets, playthings, lunch, …
Whatever you think would happen if we were discovered by extra-terrestrials, we’ve already been shouting into the universe for decades. Perhaps the best we can hope for is that the yelling is drowned out by other noise or ignored as not being worth the effort.