You had to comment, so I have to reply.

Here is what I believe. Based on my life's experience and intermittant research. I can only state what I believe from
educated conjecture as I have never had a 'close encounter', but I have on many occasions seen 'lights in the sky'.

1> Extra-terrestrial intelligence exists. Ita a mathematical certainty.
2> Extra-terrestrial 'visitations' are possible but EXTREMELY unlikely, due to distances and "needle in a haystack" syndrome.
3> If any Extra-terrestrial 'visitations' HAVE occured, then they will be very rare because they serve little (observable) purpose.
4> Extra-dimensional intelligence is highly likely, based on my own derived theory of the structure of space-time.
5> Extra-dimensional intelligence is likely, based on publicly accepted theory of the structure of space-time.
6> Extra-dimensional 'incursions' are possible but EXTREMELY UNEXPLAINABLE, due to our lack of knowledge/understanding.
The only proof we could gain would be that something solid 'materialised', moved inexplicable, then vanished again.
7> Extra-dimensional 'visitations' by travellers from "another" dimension are nearly impossible. (too long to explain reasoning)

Well, I suppose that pretty much sums up my beliefs in "aliens", most with reasons.

Now, the idea of what is "fact" is debatable.
It wasnt THAT long ago that it was a well-known FACT that the earth was flat, or that the earth was the center of the universe.
PUBLIC fact can be wrong, but they are 'what is generally accepted to be true". Still pretty weak though.
Basically, a FACT is a 'personal opinion' that you have enough 'personally experienced' proof for YOU to consider it FACT.

Now, with 'public release' systems like youtube (and yahoo-video) and the number of hits they get,
any "one-mans fact" can get accepted by millions in time, and a well-produced video can do it fast.
So anyone could put together a Ufo animation in, say, 3DGS.
Use something like Windows Movie Maker to blue-screen it onto live-action video.
Then record that with a handycam aimed at the monitor and post it on youtube, easy...
Almost instant proof that aliens have visited, and stole the Statue of Liberty...

So youtube and the like cant be trusted as proof cause its easy for people to fake for fun.
BUT REAL STUFF IS DEFINATELY IN THERE, somewhere, you just have to use your own intelligence
to sort the wheat from the chaff.

Real TV isnt much better. Its 'facts' are largely based "popular opinion" and
then filtered by the "angle" that the TV station wished to promote.
(please insert 'Government Conspiricy" here if YOU choose to)

So what is all boils down to, I feel, is this.

The word FACT is usually used wrong, and it should be internationally-illegal to be used by ANYONE
unless they hold a (internationally-regognised) university degree or diploma or some-such.

As is stands now, one man's fact is ONLY another man's opinion.