Exactly this sentiment was reported in Catherine Merridale's "Ivan's War" which explores this to some degree. Also Anne Applebaum's "Iron Curtain" has a little bit about the Soviet occupation that says much the same thing. However, this sentiment was not the only sentiment that inflamed the Red Army troops. They had also seen first hand how violent the German occupation of Soviet territory had been. Many had civilian relatives that had died under the German occupation of Soviet territory.

However, the conduct of Soviet troops in 1945 wasn't just a "bottom up" type situation. It was also encouraged by the state propaganda and policies. Penalties for violent conduct or looting against civilians were rarely enforced. Additionally, the state made a baggage allowance for packages to be sent home from troops to civilians, which resulted in widespread looting. Soldiers knew perfectly well how hard-pressed the Soviet civilians on the homefront were and many of them took the opportunity to loot German civilian property for something to send back to their family.

I was told this was the case during WW1. Was it both wars?

I recall watching and doing a report on Behind closed doors: Stalin, the Nazis, and the West, wasn't this also a case for when Russia began occupying Poland?

Please correct me if I'm wrong.