"Chris.B" <chris.b@mail.dk> wrote in message 
news:36806e20-6abd-42c0-b12a-b031878f7d59@33g2000vbe.googlegroups.com...
It is not unlikely that advanced alien races could easily cloak their
presence from us either optically or by mass psychological masking. I
am not suggesting they are doing so but it is not impossible. This
might explain the troubling differences in opinion regarding the exact
details of sightings of UFOs by experienced multiple witnesses when
the masking/cloaking/forced-amnesia system (supposedly) breaks
down. :-)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Putting your kookiness aside for a minute, consider this:

ANY craft traveling past say 50% light speed would be
visible across 1/2 the galaxy at least.  The X-ray emissions
alone would mark it as an alien craft.

Where are the trails?