Video of people throwing rocks or burning cars appeals to our baser emotions (anger, fear, disgust), which leads to faster, more intense emotional responses that TV can use to make money (by packaging our eyeballs and selling them to advertisers). TV news is very good at capturing our attention. Images of hundreds of peaceful, determined faces appeal to our higher emotions, which are not as easy to monetize.

I want to boost the signal of this image:

10,000 Strong Peacefully Protest In Downtown Baltimore, Media Only Reports The Violence & Arrest of Dozens