Even today,there're still truth,information that still remains unknown to us as citizens and individuals.One of the biggest mistakes to make in life is to depend wholly and lay so much trust on the government.
You're right the government have alot times hidden some gravity of truth from the masses cause of their selfish gains and interest and I think this is a more reason the country has being in declined of growth passed the stages it's in right now. And also when they try to recall that such truth can actually be of help to the society they look for ways to eliminate such information.