Weiss and writer-producers Nichelle Tramble Spellman (Justified) and Malcolm Spellman (Empire).
As hit seriesGame of Thronesaired on Sunday evening, the hashtag#NoConfederatetrended globally on Twitter.
We believe the time to speak up is now before the show has been written or cast.

This Sunday at 9 p.m.
ET, during @GameOfThrones, we ask you to stand with us.
We want to send a message to @hbo using hashtag #NoConfederate.
(Reign launched #OscarsSoWhite in 2015 after the Academy Awards nominated an all-white slate of acting nominees.)
We know we have the power to make change, she added in another tweet.
Lets show @hbo how many people are against #Confederate.
hey join us Sunday w/ #NoConfederate.
HBO announcedConfederateearlier this month.
I do understand their concern, Nichelle Tramble Spellman said.
The concern is real.
So I would have loved an opportunity for the conversation to start once the show was on the air.
Weve got black nephews, uncles.
Black parents and black grandparents.
We deal with them every single day.
We deal with the struggle every single day.
And people dont have to get on board with what were doing based on a press release.
Me and Nichelle are not props being used to protect someone else.
File this under hindsight is 20/20, Bloys told reporters Wednesday at the Television Critics Association summer press tour.