Do you believe aliens are real?
Why do you think so?
What do you believe is in area 51?
Does the government hiding aliens seem like a reasonable assumption?
Do you believe aliens are harmful to humans?
Sorry to get to this so slowly I've been part of that big winter storm and we lost power for a few days!
I do believe aliens are real, but feel that the type of alien most of us are familiar with, the little gray with the big eyes, has not been proven. Science is pretty firm in believing there is life on other planets, or in the case of Mars, it appears more and more likely that there was some form of life there. ANother theory that really makes sense to me is that life on Earth came from outer space. Probably travelling on some comet, which have now been found to contain all the components needed for life to begin.
Area 51 is confusing in that as time goes on, more and more evidence is "uncovered". This is unlike say your average crime scene, where as time goes on less and less is discovered. Time is the factor here, in that many people are only speaking up at the end of their lives, or it is the memory of small children. This is fairly unreliable. I think something crashed, but probably was top secret and the military took advantage of the belief in UFOs to play that up. Someone quickly decided it was a bad idea. The "proof" is all hearsay and there isn't one bit of hard evidence. Lots of stories and yet nothing found, even when researching the area the supposed craft crashed. THe military did not have all the advanced search equipment we have now, yet later visits to the site have found nothing. Also none of the stories match. Area 51 is still used by the military. A good book about the site is "Dreamland" by Patton. It details much of the top secret black ops type work that goes on there, and also interviews those that believe UFOs are real and still the subject of study there. It's a good beginning to make up your own mind.
The government hiding aliens seems a bit silly as no one can quite agree on it. Some say aliens are frozen at Wright Patterson Airforce Base. I knew someone that worked there and he was close enough to me he swore he knew the entire place and there were no hidden UFOs or aliens. One reason I believe him is he did believe in alien visitation. (he has since died) So if there were aliens, he would have told the world. Some people believe aliens are running our governments, which I would like to state if they are I wish they would do a better job. THey are not cooperating and there is an awful lot of war and distrust. An aliens super race running the world would do a much better job. It's just common sense humans with all their failings are running things, not an advanced super race.
Aliens if they are visiting aren't harmful to humans in that they seem to have not brought any super bugs or viruses with them. That would be my main worry. Think about Columbus and the Native populations in the New World. Also, no large groups of people have been killed directly by aliens, at least that would have been covered by the news. Remember, if aliens are visiting they are visiting the entire Earth, and some government somewhere is going to tell. Aliens could be harmful if a comet brings a virus to Earth that could kill humans as we have no resistance to it. Aliens could be harmful if some alien race we don't know about suddenly does visit the Earth (it may not have happened yet, but it could in the future). We really don't know what future visitors could be like. After all there are many planets with the potential for life, and I'm sure not all of them are friendly.
I hope this helps. Most of it is just my opinion.