I'm curious about this too. Use something like Tineye and check new Funnyjunk submissions against The Oatmeals image archive. Aside from the hardware it's a tiny amount of work for 1 human to monitor the results.
If the content creators don't want their content on Imgur then they should be able to take it down.
Nothing is preventing people from linking directly to the content creators site, redditors are just apathetic and would rather just click through imgur links.