Unfortunately from what I've seen thus far, it seems that it truly is both being aggressive with no repercussions and hatred and racism. Many people of all ages and backgrounds who are hateful or racist know those behaviors are not civilized or welcome in society so an increasing number take to the internet to spread their hatred with no repercussions. It's a modern way for them to spread their nonsense.
I call it keyboard courage and I commonly find myself trying NOT to read comments on newstories. They are so negative and mind blowing that I cease to never be amazed at the depths to which people sink. Without any exaggeration, my jaw drops when reading some of the sewage people spew online, most of whom are nothing but cowards who could not say these things face to face with others, much less the targets of their aggression.