On Wed, 22 Aug 2012 00:36:56 -0700 (PDT), Rupert >
wrote:

>On Aug 22, 12:56*am, dh@. wrote:
>> On Fri, 17 Aug 2012 01:04:39 -0700 (PDT), Rupert >
>> wrote:
>> >On Aug 16, 11:47*pm, dh@. wrote:
>> >
>> >> * * Then you should be able to appreciate why we wouldn't necessarily be able to
>> >> detect them, and especially if they didn't want us to. We're in no position to
>> >> go find out.
>>
>> >That is not what you said. You didn't say that it was a possibility
>> >that they might go undetected. If you had said that you would have got
>> >no argument from me. You said categorically that they would go
>> >undetected. This is the claim that I asked you to justify.
>>
>> * * If any exist it's pretty obvious that we couldn't detect any of them even if
>> they inhabit every other star system in the universe, since we haven't detected
>> any even if they inhabit every other star system in the universe.
>
>It is not valid to infer from the observation
>
>(1) We have not detected any extraterrestrial life
>
>to the hypothetical statement
>
>(2) If extraterrestrial life existed, it would not be possible for us
>to detect it.
>
>There are good reasons to think that if extraterrestrial life existed
>we would probably be able to detect it. So if one thinks that it is
>likely that extraterrestrial life exists, the fact that we have not
>detected it presents a puzzle.
>
>http://en.wikipedia.org/wiki/Fermi_paradox

If even one UFO sighting is of an xt vehicle, or any of the things
associated with ancient humans were of xt influence then it has been detected.
They apparently don't want us to have proof if they're having influence.