surely it could be possible to develop a component/app to search the web for duplicate content, determine if the author is the same, and penalize in the event of plagiarism, no?

I'm not a coder, so wouldn't know how to execute the idea - though I imagine it'd surely be possible to have a competent team write an app to auto-execute any time someone posted that could run a search and verify whether content was plagiarised or not... it might not be 100% automatable, though surely to the degree that if duplicate work was found, a notice could be sent to the poster's account with request for verification they are in fact the author, requiring action to verify - which could then update the steemit system database of their accounts on other sites which they might be posting duplicate content, to prevent further alarms...