It would be very surprising if the demonstrations we have seen in London and other cities over the weekend, do not have adverse effects on the rise of infection, and results can take over 6 weeks to show in death rates sadly.
I think it would have caused more trouble to try and ban these demos, because feelings are running so high at the moment, and the murder in US was the trigger I think, that brought to a head multiple injustices that many feel, not just in the US.
However, with regard to rising of infection, I have seen plenty of people in my age group, who initially conscientiously obeyed the lockdown, now breaking the rules quite openly. For example moving arrangements for meet ups inside when weather changed, and mixing with family openly, some of whom are key workers.
I think it is possible to track a definite change in attitude after the Cummings affair. I am very concerned about this, and that by the time the rising rates become obvious it will be too late.