Who gets to define what is racism and what isn't? And how broadly do we apply this logic? Racism is wrong and dangerous so we can censor. What about sexism? Age

Who gets to define what is racism and what isn't? And how broadly do we apply this logic? Racism is wrong and dangerous so we can censor. What about sexism? Ageism? Heightism? Extend this out and anything that can be potentially offensive to anyone shouldn't be allowed.