 What is significant about the events being broadcasted?
"The peoples of the world, then, know what they are, and know that we face the most momentous struggle in our history. They have treated us precisely as we, in less enlightened days, might have treated a newly-discovered race of lower animals. They have examined us, dissected us, driven us mad, killed us with no discernable provocation; and this is more intolerable than any normal invasion. Not only our individual lives are threatened, but our existence as a race. It was a street scene in the Science City of Manhattan, flooded by the warm spring sunshine.
 Even though the imagery is horrific, it's important that the whole world is made aware. It's their only warning.
 Without the broadcast, there is no proof of what is happening. As Peter says, it's unbelievable otherwse.  Even though the imagery is horrific, it's important that the whole world is made aware. It's their only warning.  The images are horrific. It shows the brutality of the aliens.  The broadcasts will likely lead to mass panic and suicide, because of how grim the circumstances are.