I assume this is in reference to the idea that the statement "all lives matter" is racist? Seems some explanation might help you gain a better understanding of why that is. In a vacuum, nobody thinks the idea that all races should be treated as equals is racist or offensive. Of course, absolutely everyone agrees that all lives matter. Literally everyone. But the statement "all lives matter" did not come about in a vacuum. That statement was developed as a direct response -- and intentional contrast to -- the statement that "black lives matter." The statement "all lives matter" is considered offensive, not because it has an inherently racist message, but because it either misunderstands the meaning of "black lives matter" and/or because it inherently seeks to dismiss or deny the underlying meaning of "black lives matter."
The phrase "black lives matter" came about to raise awareness that, historically and still today, institutional policies, structures, and racism have led to a situation in this country where black lives are treated to matter less than other lives. The statement doesn't in any way mean that
only black lives matter, it is just an acknowledgment that black lives in many ways have been treated in this country as mattering less and seeking to rectify that inequity.
The response "all lives matter" either fails to understand that meaning (by wrongly assuming it means
only black lives matter) or seeks to deny the underlying intent of the phrase that points out the inequity for black people in our country. And, yes, if that is the intent of the speaker, to deny that black people are in any way treated worse than white people, that intent and use of "all lives matters" is considered racist.
An analogy that has circulated illustrates the point pretty clearly. It is as if some people have their houses on fire and cry "houses on fire matter" in an attempt to get the fire department to come help them. Only to have their neighbors without their houses on fire cry back, no, "all houses matter," in an attempt to either deny that there is a problem with the houses on fire or prevent the fire department from coming to aid the houses that need help.
To sum up. In a vacuum, it is absolutely not racist at all to feel that all races should matter equally. On the other hand, it is considered racist by many to use rhetoric to undermine a minority group's struggle for equality or to use rhetoric that dismisses that inequity exists in the first place.
Hope that helps. If still confused, check out this
LINK.
(Edited to say that I don't mean to say CPJ's words were racist. Just helping to clear up a misunderstanding that seemed inherent in your response.)