I humbly present to GTers the BITLU Litmus Test for Internet Barking (BITLULTIB, I made a palindrome!) for when to tear them down. When reading an article about something someone did (all articles!) or stumbling upon a fellow commentor's comment, ask yourself which of the following four categories best describes the situation you are confronting.
Did the person have...
1. Good intentions and good outcome? Carry on, do not tear down. It is possible that this well intentioned person achieved this good outcome through less than perfect means. Maybe they forgot to include x-race and y-experience in their soundbite, maybe they slept through an important history lesson in highschool, or maybe they just are generally annoying to you 90% of the time. Oh well! People are imperfect and are individuals. They aren't you. And they may not always speak as carefully as you, or be as educated about z-topic as you, and maybe they still have some growing to do (don't we all?), but this is a win! To tear them down when they had good intentions and a good outcome undermines the progressive goal you yourself are working towards! This is especially true when we tear down people in the public-eye. It discourages other celebrities from speaking positively on a social issue, because it creates a fear that there is no "right" way to have that conversation, despite positive intentions and outcomes.
If you need to speak about the issue in the method, divorce it from what happened and do not insult the good-intentioned, positively-contributing person. Example: "Let's talk about appropriating x-thing. Why does this happen? Is it ever ok?" It's a sidebar.
Full disclosure: I was inspired to write this post at midnight after reading comments critical of Lena Dunham's comment on her sister's coming out. I believe Dunham belongs in the good intentions, good outcome, imperfect phrasing category. This test determines that she shouldn't be insulted or torn down, because it undermines the overall positive contribution that she made. We need to be more generous to one another. We're fighting for the same progress. We need to stop cannibalizing ourselves.
2. Good intentions and bad outcome: Gently correct and educate the person. Do not insult. Think back to stupid, problematic things you said when you were younger or less informed. Remember the person who taught you what you now know and emulate them.
3. Bad intentions and bad outcome: TEAR 'EM A NEW ONE! Or educate them if you think they are willing to listen and aren't trolling. Or maybe you are a champion of this issue, in which case, champion away! Your patience inspires awe; you're a unicorn. Anything from levelheaded, carefully constructed persuasive essays to sassy gifs are fine.
4. Bad intentions and good outcome: This is the tricky category. If it's a really good outcome, then swallow your need to fart on the bad-intentioned person (it is difficult), look the other way, take the win, and snicker gleefully at the dumbz. Sometimes the good outcome is so good that it speaks for itself and how it got there loses relevance fast. If you MUST say something, I highly recommend a subtle gif in which a football (soccer) player scores an own-goal then sinks to the turf and looks utterly distraught. I mean, that's basically what happened. Though, if they're villainous and the good outcome was minor, haha ok call them out on duplicity/pandering/dumbz or just rip them a new one, preferably through sassy gifs. I'M ONLY HUMAN. I can't resist.