I think the best thing people can do (and are overwhelmingly doing) is to counter that abuse with positive and supportive statements. The social media platforms have the power to ban users, and hate crime laws (while I might not personally agree with them where they only involve use of language) already exist as a means of redress for anyone who is being abused.
I am noticing the steady flow of articles in the press about how awful this is with a definite undercurrent of “something must be done, restrict people’s freedom of expression further please, government” and given that’s something the government have already made clear they’d love to do, it’s the last thing I want to see happen. Personally, I think it’s better knowing who the racists are than forcing them into silence and underground but it depends what people value more - The opportunity to confront and perhaps change the minds of people with opposing views, or for them to just be silenced so no-one has to see it or feel bad, but for their views to go unchallenged once they, as Boris put it “crawl back under their rock”. Hidden, yes. But also safe from criticism. Better to have these discussions in the open where it can be made clear that plenty of people disagree and are willing to stand up to them than allowing these views to fester in the dark, where resentment that they are being persecuted and the likelihood of them simply doubling down can only grow.