Because there were no cameras at the time to generate evidence, leaving it open to pretty much infinite straw man.
Also, define truth.
The 'truth' presented in what most people would consider a reliable source. For most people that is the media, which in reality is what the nearest government wants you to know. It might not necessarily be what really happened.
Like the Wikileaks issue- the US Government has manipulated the media to portray Wikileaks as some kind of terrorist organization instead of the simple conspiracy reporting site that it intended to be.
What's really true in that case? We may never know, as the government will never admit the truth straight up, while wikileaks cannot maintain a reliable source because it gets found and removed too quickly.
Problem is, people are more inclined to believe and obey the government in fear of legal retaliation if they don't. So Wikileaks gets labelled evil in the eyes of the public purely because the government said so. And all of the credit processing companies are reacting to that, terminating business relations in order to save their own necks.
But there is no legal action against the people from the government. I don't see what there is to be afraid of. There have been major cases in the US history in which the people won in a court. Hell, we overthrew the rule of Great Britain and became a nation ourselves by going against a government.
But if we tried that again we'd be labeled terrorists, anti-american, contributing to insurrection, along with 1,000 other misnomers.
Even though overthrowing the current corrupt government with one that actually cares for its citizens would be the most patriotic thing to do.
Exactly the problem.
Devil's Advocate for a moment here:
What if the terrorists cause is actually right? That we're an uncivilized disgusting filth of a civilization led by a government so badly corrupted that even the devil himself would be forced to stand in line with everyone else for the scraps at the bottom of the soup pot while all the aristocrats have everything. We are literally living the world of George Orwell's 1984, although still under the guise of Democracy and freedom that is very rapidly being pulled out from under us.
Think about it this way as well.
The US Government controls who is listed as terrorists.
The Government is powered by financial interests and a thirst for power.
Therefore, in the interest of self-preservation the collective consciousness of the government would automatically label anyone that questioned it or openly challenged it a terrorist, thus depriving them of the resources they would need to be a serious threat.
This could become a major issue, because even though the founding fathers encoded into the constitution our right to someday overturn our government if it began to ignore our needs, the government that is now will happily ignore said right and fight to the death to protect itself.
-Thomas Jefferson, Letter to William S. Smith, November 13, 1787"God forbid we should ever be twenty years without such a rebellion.
The people cannot be all, and always, well informed. The part which is
wrong will be discontented, in proportion to the importance of the facts
they misconceive. If they remain quiet under such misconceptions,
it is lethargy, the forerunner of death to the public liberty. ...
And what country can preserve its liberties, if its rulers are not
warned from time to time, that this people preserve the spirit of
resistance? Let them take arms. The remedy is to set them right as
to the facts, pardon and pacify them. What signify a few lives lost
in a century or two? The tree of liberty must be refreshed from
time to time, with the blood of patriots and tyrants.
It is its natural manure."