They are spreading awareness which is better than doing nothing, so yes even if their intentions aren't as pure as you think, it's significantly more useful than what you're doing now, which is complaining, so if you deem them useless surely you are marginally more pointless than they are. Complaining about nothing
Tell me what do you want? Is it immediate justice? The world doesn't work like that and no majority white country is going to be vengeful over the death of a Muslim immigrant girl who they'd perceive to also be black, at the hands of another white person no less
So the only way to achieve adequate closure towards the family is by spreading awareness through social media and pray that it all goes well, these 'clouthchasers' lead to petitions, petitions lead to donations, it's not justice but it's the next best thing these grieving people need and all hope they have left, I don't like that it has to come down to the internet but that's the world we live in.
Unless you want it to stop? Do you want the awareness and everything to stop?