Personally I think that the members of the Black Lives Matter movement are very brave, and I commend them for their efforts, but this is creating a racial divide. All lives matter, whether Hispanic, white, Asian or black, every single life matters and it's up to us to create a unified movement against racial violence.
As I understand it, the Black Lives Matter movement is about reducing or ending needless law enforcement violence against minority citizens. Wanting to stop violence is completely inconsistent with retaliatory violence against cops, as that only deepens the cycle of violence between blacks and cops that everyone should want to stop in the first place.
The recent events of police officers being injured and killed has happened at the hands of a select few people, people that are not a good representation of the BLM movement. It's unfortunate that they seem to be tainting the movement with their actions, but that is exactly what is happening. This has turned into a blame game, with everyone taking sides and attacking the others.
Indeed, extremist fringe groups often hurt the reputation of their parent organizations. For example, radical Islam has negatively impacted Islam as a whole in the minds of many people. Once radical actors make dangerous decisions, these can be extrapolated upon a larger group that does not support them in any way.