The Soviet Union is known for many disturbing things, mainly the fact that they tortured and starved their own citizens! Red Terror is the most famous campaign led by the Soviet Union where many of their own citizens were arrested, executed, and even tortured!
How does this relate to Game of Thrones? In one of the scenes of Game of Thrones, a rat is placed into a heated pot. The rat then, feeling the heat from the pot, would gnaw at the victim's body trying to escape. Turns out, this is actually a real method of torture that was used during the Red Terror. They used metal tubes instead of pots, but the idea was the same.
This wasn't the only form of torture used by the Soviet Union during Red Terror! Some victims were forced into barrels with nails as studs on the inside, and others were buried alive! Why did the Soviet Union do this to its citizens? What other forms of torture were there? Check the source for more info.