Possible answer to Fermi Paradox: "Too much energy is required to go exploring"

And the contacts that may have happened may have been unlawful. Perhaps they must be kept seekrit so that when the legitimate contact does happen, and the Interstellar Squid announce themselves, they can officially say they've followed the rules and we are a self evolved species, not uplifted by such and so and therefore their property.

see some of the works of David Brin (uplift) and Jerry Pournelle (King David's Spaceship) for further nods at those ideas.