Commenting (whether it be on a blog, a Facebook page, or via Tweet) is a fine art.
Some people get it right, and are effective in rallying other readers behind their cause. Others are looked at as Internet trolls, people who have absolutely nothing to add to the conversation.
Look, it’s really easy — we get it, the Internet is an anonymous cesspool of interaction, allowing anyone with a screen and a keyboard to shout out whatever they feel like, at any time they’d like. The First Amendment does protect those folks in saying whatever they want, but the First Amendment doesn’t guarantee that they can say it wherever they can. That’s why the DELETE and BAN buttons were invented.