The BLM thing is neither black nor white. Are there extremists and racists in the group? Yes. Are they often supporting black men who were in commission of a crime and subsequently resisted arrest? Yes. So the movement does have its shortcomings.
However, for every Michael Brown there is an Eric Garner. Or a black man being shot in the back and the cop planting a tazer. To anyone who pays attention, there ARE issues, and there are racist police. Black people get pulled over while committing no crime for "matching the description of a suspect." That's something that is seldom done to other races. Then, there are many cases where a black man is charged for matching the description, only to be convicted, and later exonerated by DNA testing. Ever notice how the cases that get set free after a decade in prison tend to be blacks? The system does appear to not work as well for them.
The problem is BLM goes looking for racism where it is not all that evident. It becomes a cry wolf scenario. They also accuse systemic racism when the real guilt is at the individual level. They need to focus on the clear cut issues, which exist. Is there a lot of ignorance in the movement? Oh yes. Is the movement ENTIRELY baseless? That's quite a bit harder to answer.
To call the organization racist or terrorist is going a bit far. Every movement has its problem children. I know I don't like being lumped in with the worst of my kind. I'm a conservative, yet there are many fellow conservatives on the fringe I'd like to distance myself from. I hate when I'm accountable for the worst of my ilk. So I extend the benefit of the doubt to BLM that they were not complicit in the shootings, etc. To say that all BLM is guilty is just going a bit too far.