Take a look here:

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Presumably you know what this is but if you don't here is a little introduction to it.

Originally Posted by :
The five-pointed red star, a pentagram without the inner pentagon, is a symbol of communism as well as broader socialism in general. It is sometimes understood to represent the five fingers of the worker's hand, as well as the five continents. A lesser known suggestion is that the five points on the star were intended to represent the five social groups that would lead Russia to communism: the youth, the military, the industrial labourers, the agricultural workers or peasantry, and the intelligentsia. Karl Marx and Friedrich Engels used the red star as a symbol[citation needed]. It was also one of the emblems, symbols, and signals representing the Soviet Union under the rule and guidance of the Communist Party, along with the hammer and sickle. The star has since become a symbol representing socialism of all varieties.
Red star - Wikipedia, the free encyclopedia

Climate change activists at Kingsnorth coal-fired power station protest prepare for jail | guardian.co.uk

Let there be no doubt about what this is all about. CO2 it is not.
[Rep]

"The five-pointed red star, a pentagram without the inner pentagon"

In other words, not a pentagram at all. But hey - why not stick in a reference to the black arts just for the sake of it. Anyway, pentagrams are (if used properly) ALWAYS done in outline. Otherwise it would serve no purpose.
[Rep]

Well it is on a black background. I suppose that means 'anarchist communists' or something. This is not the only reference to these people thinking they are anarchists either; they had some big anarchist flags at the last one, so that there is no doubt what they represent. The only trouble is that it is the government that is behind this.

Have I ever said though their ideas make sense though? I'm just the reporter and that was just a quick copy and paste from Wikipedia. I only included it for the benefit of those who were wondering of the significance of the red star. They are very strange people indeed.
[Rep]