They are taking advantage of the widespread ignorance about the Law of War and the Law of Nations. The legal profession has long been both an unreasonable interference in the military arts and at the same time an unrerasonable abuser of individual rights in the military role of judge advocate. Matters are not helped at all when you take lawyers already predisposed to irrational Leftis ideologies, and then you have to deal with their gross ignorance of this subject matter and its historical underpinnings.
Like the Seeond Amendment debates, however, the laws regarding combat by person not commissioned or enlisted in service to a sovereign are subject to misrepresentation and re-writing by organizations such as the ACLU.