You are framing it to sound very scary when its a short lived breakdown in law and order. A lot of people involved were not motivated by any particular ideology, but were just taking the opportunity to do things like looting. There is nothing that I can see in fascist ideology that motivates people to loot a Greggs.
It is very much what the media are doing: one local news website compared what happened in their town to Kristalnacht when what happened was 12 houses had windows broken and some cars were vandalised. Nasty, but hardly a fascist takeover.
On the other hand, the media do not balance it with equally wide reporting of things such as local builders doing free repairs on mosque in Southport, or the far larger crowds that turned out for counter protests.
Crime IS a normal occurrence. Riots will happen. You should not compromise human rights to deal with it.
There are blatantly racist social media posts - FB is infested, and I agree showing such posts so widely (no doubt because they get high engagement because people feel impelled to disagree with them) shows FB in a bad light.
One alternative is using the huge footprint people have left on social media (to say nothing of phone location data) to catch the people involved.
As a brown British person the riots have not caused me any great concern (contrary to what some posturing politicians may claim). Yes, it might be different if I lived in an area very close to where a riot occurred, but most people do not. I still think the UK is a lot less racist than the other countries I have lived or worked in, or no anything about, and a lot less racist than if was when I was young.