Black Lives Matter

black lives matter movement doesn't mean anything until they address black on black crime

This is essentially saying unless it is perfect it is worthless. Perhaps a Nirvana Fallacy .

 i cant support them until they say ALL black lives matter, bc they clearly don't to them.

If the person believes this, then this would appear to be a reasoned response. It could be pointing out the hypocrisy in the movement, if this were true. However, the claim that some black lives clearly don't matter to them may be unwarranted.

black lives matter movement doesn't mean anything until they address black on black crime,

Logical form:

Black Lives Matter (BLM) means nothing unless it addresses black-on-black crime.

BLM has not addressed black-on-black crime.

Therefore BLM means nothing.

The conclusion follows from its premises in logical terms, but the argument is unsound because the major premise ("Black Lives Matter (BLM) means nothing unless it addresses black-on-black crime") is false . There are multiple issues facing African-Americans in the US, with police brutality being one of them. BLM are choosing to focus on this by making criticisms of police attitudes and methods with the aim of changing these and thus improving relations between black people and the police, which will alleviate one of the issue faced by African-Americans. This is clearly meaningful. 

i cant support them until they say ALL black lives matter, bc they clearly don't to them.

"Black Lives Matter"  does not imply  that other lives do not. This is like suggesting that, if I express a like for a certain food, that I dislike all other foods. For instance, if I say I enjoy eating apples, and someone says, "so bananas are not good?" BLM is not making a comment on other lives; it is making a comment on black ones, and suggesting that, based on the way the police currently treat African-Americans, that black lives are not considered important - hence the phrase, "Black Lives Matter". Adding 'all' does nothing to the veracity of the claim.

These criticisms of BLM are really weak. A shame, given that decent critique of their methods, ideology and demands exists.

"black lives matter movement doesn't mean anything until they address black on black crime"

This is also framed as a False Dilemma Fallacy. If they address black on black crime then it means something, if they don't address black on black then it doesn't mean anything, which is black and white thinking.

"i cant support them until they say ALL black lives matter, bc they clearly don't to them"

Black Lives Matter is just a slogan, but people take it as a literal claim, which its not. So its a kind of Equivocation Fallacy regarding the different possible meanings of the slogan.  

And yes, this can also be interpreted as a No True Scotsman Fallacy as well. 

The idea that blm "doesnt matter" until they tackle the black-on-black crime problem is pretty illogical, i dont even know what these people mean about "black-on-black crime", claiming that black commit a lot of crime against black people is a claim wich needs evidence, and even after doing some research on google i couldnt find any, so this claim is unsubstancied and apperantly cannot be substansiated, All lives matter or All black lives matter is a sentence usually saind in response to black lives matter, people who say that are usually white supremacists and by "all lives matter" or "all black lives matter" they are actually suggesting black peoples lives are not really that important. https://en.m.wikipedia.org/wiki/All_Lives_Matter

Suggesting that the blm movement dont care about black lives is pretty stupid and an Ad Hominem, the blm is about FIGHTING racism, so it doesnt make sense to assert that its the opposite unless there is event wich these argument dont provide, but the argument is actually not really a No True Scotsman but rather an argument full of claims without evindence that require and  an argument that uses a racist slang.