Why do government hide things from us?

Would we feel safer or more scared?

The things we know are things the government has decided to let us know. However there is justification of why they do this and that's this permanent question of "would we feel safer or more scared if we knew the truth?"

Crime and terror

Lets start with crime and terror. Whenever we see a crime on the news its usually to do with murder because its more interesting to read or hear about than something like a person who refused to pay his parking fine. But what about crimes which only get a bit of media attention. the things that the government doesn't want you to know to make you feel safe and not worried to go out.  For example lets say a news story is that a group of men tried to burgle a huge shopping centre whilst armed and tried to enter from the roof fire escape. For all we know this could be complete truth but what if there intention was not to burgle the shopping centre. What if it was something more serious like a terrorist attack with anthrax. Anthrax is a chemical which disintegrates in the air and kills anyone who inhales it within a few days. These sort of things do happen and are given a cover story. But the government could never tell us the truth of this because it creates a huge amount of fear for the whole population and once the whole population turns fearful how do you calm the situation for the millions? quite simply you can't so they have to hide these things and they are right in doing so. Terrorism is the crime the government hides most for obvious reasons. What do you think? should we know of all crimes in their entirety ?

ALIENS

another controversial topic which everyone loves to discuss is aliens. Not much can be proven if aliens exist or not. However there are stories and articles about UFOs (Americans like to coin the term weather balloons) and alien encounters. Roswell was the first ever supposed human encounter with an alien. He claims he saw the alien and there was debris of a space craft there. How coincidental is it that this man was killed by the government and took all the debris away with them. Which is why I strongly believe there are other life forms out there. I also believe that when we see alien toys or lunch boxes or novelty items or cartoons/movies with aliens in they all look quite similar and usually have a large head and big eyes.

food

movie

video game

cartoon

All of this can be coincidental or it could be "Hollywood" stereotyping what an alien looks like and designers carried on the tradition of making an alien look like this but some people believe this is the governments way of subliminally sending messages to the general population that if aliens did find a way into the general publics eye then we know what they look like and wont be too freaked out when we see them because media has already shown us what they look like.

Area 51 is another thing associated with aliens. Some people believe aliens are experimented on there and others believe that its a secret military base testing new spy planes and weapons. All though there is no proof of what goes on there, there was a documentary recently interviewing people who use to work their. Is it legitimate or is it just used to put the publics mind at rest. the interview is available here http://seattletimes.nwsource.com/html/localnews/2011461015_area51vets28m.html

So should we know everything that happens or should we not?