Please use the icon when you see disruptive or antagonistic comments or any other violations of the Community Rules. This serves two purposes:
1- using the icon will bring that post to the attention of forum moderators so they can deal with it appropriately. We prefer that you not respond to the post directly. Responding invites the offender to continue, and if you respond aggressively you may end up dragging yourself down with the offender.
2- if enough users flag a post using the icon then that post will be hidden from general view, preventing others from being exposed to it.