Saturday's violence in Charlottesville, Virginia is bringing renewed attention on an old problem plaguing the country -- white supremacist groups and extremism. Experts say white supremacy started to reemerge from the shadows a decade ago and the Internet has helped in the growth and re-branding of an old idea.

The killings of six worshippers at a Sikh temple in Wisconsin has thrust attention on white power music, a thrashing, punk-metal genre that sees the white race under siege.