Read about how the hashtag got started here.
“The hashtag was originally coined by blogger Mikki Kendall during a Twitter debate about Hugo Schwyzer, an American academic and self-described “male feminist”. Schwyzer has been accused of harassing non-white female bloggers and recently wrote that his critics drove him offline.”
You can also read tweets with the hashtag here.
And you can see a Jezebel article here where many people in the comments call out the blog for praising the hashtag but erasing the WoC who created it.