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Nothing intellectual to add? That may be my favorite 'put in this whole discussion. *That* I could at least remotely visualize, that a bunch of alien species made friends and the Board voted to conceal itself from us.
Still don't buy the idea that they'd be able to erase every fingerprint over the past 1,000,000,000 years, or that they wouldn't step in to ease suffering, or that some renegade species wouldn't have done something catastrophic, and all that stuff. It's as quiet as the tomb out there, which looks more like "nothing's there" than "they're real good at hiding."
But there are a few scenarios like this that at least don't sound *to me* like Pixies Stealing the Socks. :- )