Brown is public supporter of GLAAD's Together movement and has previously voiced support for Parkland shooting survivors.
It's safe to assume that the tirade against Brown was timed to coincide with pride week in an effort to attack the young star's character.
The meme is thought to have originated as an inside joke from within the LGBTQ community.
Millie herself frequently posted on social media, updating on her whereabouts and posting sweet messages with boyfriend YouTuber Jacob Sartorius.
Since the memes came to prominence and Brown deactivated her Twitter account, fans have been calling out those who made the memes.
There's a history of users bullying public figures on social media, until they've decided they've had enough.
The memes depicted the actress saying homophobic quotes and have been removed by Twitter in the wake of the incident.
Brown will return to play Eleven in the upcoming third season of Netflix's Stranger Things.