On disrupting meetings
I've disrupted some meetings in the past, now and then
Looking back, I think it was sometimes productive and sometimes not
IMO it can work if it produces enough controversy for people to talk about the issue later over their dinner tables, provided enough are likely to reach the conclusion you want them to reach -- and that means the topic must be serious enough to merit attention and that the disruption must coupled with a well-focussed educational effort
The following information has been collected from FBI Supplementary Homicide Reports: it considers cases where a single male fatally shoots a single male stranger; about 2600 such cases were found in the FBI data 2005-2010; and the percentage of cases, where the homicide was ruled "justified" has been tallied by perceived races (white or black) of shooter/victim:
B/W 8.6%
B/B 10.1%
W/W 16.3%
W/B 42.3%
Overall 14.9% of the cases, where a single male fatally shoots a single male stranger, were ruled "justified"
See this pdf: the data here was intended to examine cases like the death of Trayvon Martin but might also shed light on the death of Michael Brown
It seems to me that BLM is raising a serious issue and could win dinner-table conversations on that issue