Can someone explain to me what the Black Lives Matter organization is about and why some people are so upset about it?

I don't think that's what they're doing at all. They're putting the disproportionate murder of black citizens by policemen on blast

@UnparalleledMonster: They do not think it may be disproportionate because te number of crimes committed by blacks regarding the wholw American population is disproportionate?

@Cierzo: I think they're upset by killings of unarmed and/or surrendered or fleeing black men

@UnparalleledMonster: It is upsetting and unacceptable that unarmed people are killed by policemen. But instead of wondering why the causes of the issue as a whole and try to find solutions, they try to make it appear as a 'white cops hate black people' thing.