I'm sure this has been suggested elsewhere, but nothing came of it, either way, and it has come up again in a conversation with another member by PM.
Currently, Instructables can be flagged for three reasons - "inappropriate", "incomplete" or "spam". Whilst they cover most eventualities, I would like to propose a fourth flag option: "other".
Of course, "other" is rather vague, so its use would require details - clicking it would open a comment or message box to allow a brief description of the reason for the flag, whether it is the original source of a project that has been ripped off from elsewhere, or a concern regarding the safety or legality of a posting.
I don't know coding, so I don't know if such a system is possible with this site. If it isn't, then can I suggest that a fourth flag option be added called "Legal issues", or some other catch-all phrase that covers issues of intellectual ownership and site liability.