Not sure if this counts as a single act, but the Nazis looted and stole a ton of money
It was one of the greatest thefts by a government in history; the confiscation by Nazi Germany of around $580million of central bank gold -- worth around $5.6 billion at today's prices. The gold came from governments and civilians, including Jews murdered in concentration camps, from whom everything was taken down to the gold fillings of their teeth. BBC diplomatic correspondent, Barnaby Mason, explains the issues at the core of this week's London conference, which aims to lay the issue finally to rest
What is Nazi gold?
When German troops invaded countries across Europe in the late 1930s and early 1940s, they looted central banks and carried off hundreds of tons of gold to finance their war machine. The Nazis had exhausted their own gold reserves, and historians believe that any gold passing through Germany after 1939 was almost certainly looted.
The Nazis sold gold to Switzerland and other neutral countries such as Sweden and Portugal. It's hard for these countries to argue now that they didn't know the gold was looted, though the Reichsbank often melted it down and put its own stamp on the bars with a fake pre-war date.
The SS also collected gold stolen from Jews and other victims of Nazi persecution, including jewellery and gold teeth from the extermination camps; some was sent to the Reichsbank and melted down.
It's impossible now to determine how much of the gold came from individual victims, even with sophisticated scientific tests. Some Jewish groups have suggested up to 10%; the British government talks of a minute proportion.