The biggest injustice that was perpetrated on people, tricked or forced to accept communism, was the destruction of the human spirit, the terror, torture, and brutal beatings people had to endure in the name of social justice
Under communism we had all types of justice you progressive drones are demanding during your violent riots: gender, environmental, social, reproductive, and food justice, long before the millennial snowflakes started asking for safe spaces, crayons, and animals to pet because they are afraid of reality, and long before the regressive left started inventing new ways and outrageous euphemisms, such as "white privilege," to claim and steal other people's money, goods, and services they have not earned.
For starters, we had food justice, one for the proletariat and one for the communist elitist apparatchiks. It was not the kind of food justice you are demanding, free and fresh food from the government.