Here's my thoughts on the issue (I used to like to read about this sort of stuff, so I thought about it a lot back in the day when I sat at home on Friday nights haha):
The universe is HUGE. My science teacher recently told me if you hold a grain of sand out at arms length in the night sky you would block the light from 100 million stars. With that many stars out there, and each one with its own planetary system around it. There has got to be life out there somewhere, even in multiple areas throughout the universe. Just because we haven't discovered any life yet, doesn't mean that it isn't out there. I'm positive that there is much more life out there than we can even imagine, the universe is too big not to field more life than just out planet.
Now, since there is most likely other life out there (and probably a lot of it) then there has to be some intelligent beings out there also. NASA is constantly sending signals out into space trying to reach other beings, but we have gotten no response back yet from any other planets. I've heard that by the time one of these signals reaches a far out planet, it could be a hundred thousand years from now (since they travel at the speed of light, to reach a galaxy 100,000 light years from us would take 100,000 light years.) Then to get a response would also take another 100,000 years, so we can't expect a response anytime in our lifetimes to let us know that there is other light.
But there could easily be some advanced way for other life to detect these signals early, and if they can detect us, and know we are here, why would they want to contact us, an obviously inferior lifeform to them. Humans are incredibly paranoid of other humans, think of how paranoid we would be of other beings from other planets. The same would most likely go for any life that would be advanced enough to detect our signals before they reached their planets 100,000 or even 100 million years from now. They could easily watch us without us even knowing about it, or having any clue at all about their existence.