The hashtag was used to spread stories - many of them with outrageous details - falsely linking Brown to homophobia.
Other social media users expressed support for Brown, who remains active on Instagram.
Numerous posts attribute obviously false quotes like "We don't need gun control, we need faggot patrol" to the British star.
"Wowwwwwww humanity really is the worst", one person tweeted.
Scottish Nationalists in walkout after their leader is expelled from the Commons
This week, the Tory Government chose to press ahead with its power-grab to keep Scotland's powers in London - not in Scotland. SCOTTISH Nationalist MPs stormed out of the Commons after their Westminster leader was expelled by Speaker John Bercow.
And another obviously doctored image says: "I hate the word homophobia". She also still has her Instagram account, but has deactivated the comments section.
"Stranger Things" star Millie Bobby Brown has quit Twitter after some users shared memes attributing homophobic, anti-gay comments to her, according to several entertainment publications, including People.
"You are grown adults, editing photos of her with captions that include the f slur, violence against lgbt community for comedy and it's f**king gross".
The memes depicted the actress saying homophobic quotes and have been removed by Twitter in the wake of the incident.
The memes started with a few that said the child actress ran over gay people at Pride and was happy about it.