As with almost everything in this world, there are positives and negatives to how quickly and easily we can communicate with each other nowadays.
Although it's life-changing to have access to all the information in the world and to have so many choices for who we choose to share it with, so too do those on the darkest fringes of our society.
Not only are these elements able to spread whatever hateful misinformation they want, but they're empowered to create echo chambers where they can have their viewpoints reflected back at them several times over.
And when this happens enough, they can be emboldened to take their hate out into the world and do something like the suspect in today's story has.