useful idiots for the banking class

Lenin said about capitalists: "they would sell us the rope with which we would hang them," and he meant it (and was right, starting with the Germans who sent him to Russia). "Useful idiots" was his expression and he didn't see himself as "banking class" in his total war for a global classless society. His propaganda singled out the Russian and foreign bankers (depicted in posters as piglike creatures in top hats) for special hatred, to be smashed by the worker army without mercy.

Marxism

Marx set the ultimate goal of his socialism as the abolishment of money (among other things). Only then communism would be achieved.

Extreme Marxists (of a more-Maoist-than-Mao kind, radicalized in France) in Cambodia actually did this right away. They ritually blew up the banks, scattering now-worthless currency in the streets.

Their RAF brethen in West Germany, when not kidnapping or assassinating police officials and leading capitalists, or bombing American soldiers and hijacking planes carrying Jews, often robbed banks.

In Russia, Stalin himself had began his revolutionary career as an extremely violent bank robber (dozens killed in just one heist). The Bolsheviks then executed countless bankers after seizing power with their coup.

According to the official history of the Central Bank of Russia,

On 25 October (7 November), the Bolsheviks occupied the State Bank premises in Petrograd. Bank officials and officers who did not recognise the new authority went on strike. In November, the Bolsheviks took control over the State Bank in Petrograd. After a decree was adopted in December about the nationalisation of banks, a state monopoly on banking was announced. At the same time, a decree on the inspection of bank vaults was adopted. Gold bullions and coins were confiscated and transferred to the national gold fund. Decrees were adopted according to which Russian government loans were cancelled and the equity capital of former private banks was confiscated. http://www.cbr.ru/eng/about_br/history/

There were many various strikes against the Bolsheviks early on, because Russian people were used to use strikes as an economic-political weapon against the previous, not ruthless regimes (especially during the revolution of 1905). The Bolsheviks then dealt with the strikers through such measures like drowning them en masse under the ice or in sunken vessels, killing thousands this way in just one city. They also gassed the peasants who opposed giving away all their food to the soldiers and starving to death, and so on. (In all as many people died in the Russian Civil War as in half of the entire World War I anywhere.) Lenin also actually proclaimed communism, but it was his own special "war communism" where everything is for war effort and people don't matter.

Marx also directly connected the concept of money with the Jews, who he said too should be abolished (On the Jewish Question).