Initially a response to George Zimmerman's acquittal for killing Trayvon Martin in 2013, Black Lives Matter (BLM) has become a rallying cry for a new generation of Black activism. The BLM movement focuses on intersectionality in the Black experience and, from the Black Lives matter website, "It centers those that have been marginalized within Black liberation movements. It is a tactic to (re)build the Black liberation movement."
From the same website:
When we say Black Lives Matter, we are broadening the conversation around state violence to include all of the ways in which Black people are intentionally left powerless at the hands of the state. We are talking about the ways in which Black lives are deprived of our basic human rights and dignity.
It is self-described as a movement of "Black self-determination" and is, most notably, focused on the discriminatory regulatory, judicial, punitive, legislative, and judicial practices that disenfranchise the Black community.