There's a video on the Twitter account in the op that lists some names, but I'm not familiar with them.
I think one if their vids said eight people of colour have been killed by police in the last six months.
The video says 3 in the last 8 months.
Seems investigations are opened in all - as it should. One might have had a gun in his car and two other people in the car are charged with "
plotting to help release two prisoners from a van as they were being brought to Wood Green crown court that day for sentencing."
One kid was stopped by security in a shopping center and died later. Might be medical, can't find clear conclusions from it.
One woman was moved from a hospital to a prison after an assault (in self defense maybe) and died there. She had mental health problems it seems, so should never have been moved.
They mention Mark Duggan on Twitter. Someone was convicted of handing him a handgun later on. I don't know if he is the guy to put on your posters.
And they are also putting the deaths with the refugee crisis in the video. Don't know how that is related.
Every death is one too many, but I don't know if I'd call it a systematic problem with police brutality against black people like we've seen in the US too many times.
Maybe the movement in the UK is more focused on racism in general then?