GDPR's Right to Access and Right to be Forgotten states that if any member of the EU can request to have all of the personally identifiable data that's associated with their name compiled and copied for their use, or even erased completely from your database. https://www.eugdpr.org/the-regulation.html
They are not required to provide businesses with a list of all the forms they've ever filled out, so the only way to do this in Machform is to open every form individually, search the entries in that form for their name, delete that entry, and then move on to the next form. I don't know of a way that exists right now to search by a single person's name and have Machform return all of the entries across all forms associated with that person either to export for that person's records, or to erase in its entirety.
Is this something we can do now, or is it currently on the future feature list? Since the new GDPR comes out on May 25th, a lot of people should be looking for this feature.