zylgchs 
Cynosura
Normally people would say all lives matter because it is true, like this image made three years ago (is saying in some way). Right now people are saying black lives matter because there are existing implications that some people think black lives doesn't matter and BLM is used as a counter-statement. Both sayings are valid in their circumstances.
On a different note, I believe drawing a character say something that will fit in their universe while also expressing your point in a clever way, like in this image, is MUCH better than having them shout/wave a IRL slogan.
On a different note, I believe drawing a character say something that will fit in their universe while also expressing your point in a clever way, like in this image, is MUCH better than having them shout/wave a IRL slogan.