[user104658]

Originally Posted by Liam-

Can you think of any other reason angry white people would shout it at people protesting for better treatment for black people?

I personally think you give people too much credit in assuming it to be racism in the majority of cases. I genuinely think a lot of these mouthbreathers just genuinely think that people who are saying it mean "only black lives matter to them" and they get butthurt about it. Which is more "unfathomably stupid" than racist.