This from Donuel further up the thread:

"Now that most people have a camera available everywhere, where are the remarkable ufos? ...

Either the universe has expanded to non visitation distances or they did not exist at all ...

I'm hoping I am wrong.

If there is a cost risk decision to be made by aliens we may be decidedly too dangerous."

Thinking about 'UFOs' and aliens recently, this occurred to me:

Although some of us may think we're 'Masters of the Universe' we actually inhabit an infinitesimally tiny bubble in space-time. Only at this end of the time dimension have we even begun to understand our place on this planet and the wider Universe, to develop the technology to communicate via radio waves and other electromagnetic media, leave this planet and explore the Solar system etc., etc. Interstellar travel may or may not be possible (it appears to be impossible at this point in history) but, the way things are going, we may not have enough time to develop it even if it is possible. We're destroying the biosphere, contained within the spatial dimensions of the 'bubble', at a ferocious rate of knots. We've probably only got a handful of generations to go before we render ourselves extinct.
Now what if technological 'civilisations' are rare (certainly, solar systems like ours appear to be rare) and only crop up every few million years, develop sophisticated science and technologies at the very ends of their time dimensions, destroy their biospheres and become extinct? Perhaps a technological civilisation existed around 50 million years ago in our part of the Galaxy and another one won't be along for another 20 million years. If that were the case, we'd probably never know about them - especially if they never had time to develop interstellar travel.