sickle is for countrymen, who works at farms (I hope you understand, coz I don't know the correct translation in english), and hammer is for workmen, who works in factories and so on. It symbolised the unity of the working people.
But nevermind, it was just a little excursion into history. If this represents your view, so be it.
I think I have seen that as well. Then again, they also took a symbol as common as the up-pointing arrow and if you knew its significance, that symbol would be ruined.. [link] Nazis ruin everything for everyone else.
well, about the stars :the stars were used by americans before communism. and the colour has a lot of matter, only red star is communist/socialist. a white five-pointed star isn't communist, nor a blue one etc...