Some Plagiarism plugins require the student agrees to an EULA but by the current API hooks are all post-file submission so it's hard to implement this in a user-friendly way (EULA's are nasty things anyway)

The assign_submission_plugin class uses the function get_form_elements() to add form elements to the submission page - The plagiarism plugin could add the EULA check directly to the submission page and prevent the form submission unless the EULA is accepted.

I haven't looked to see if the forum or workshop modules provide a location where we could add this but we could implement it in the assignment plugin first.