The Stockholm International Peace Research Institute on 1st August published a commentary saying that new developments in the 3D-printable gun case have revived the debate on the dangers of 3D-printing of firearms and the sharing of their electronic blueprints online. While these developments may only have a limited immediate impact on the proliferation of small arms, this approach has the potential to undermine controls on 3D printing and export controls on technical data more broadly. It says that enforcing controls on intangible transfers of technology, such as the sending of digital files via e-mail or the sharing of data using cloud computing services, is inherently difficult. Making such technical data available for anyone to access and potentially download, including to persons in a different country — rather than actively transferring them — is also covered by export controls. It says that export controls on the technical data required for the development, production, operation or repair of a controlled item to date provided the main regulatory measure on 3D printing; and from an export controls perspective, the removal of such controls on technical data is (or would be) a worrying development. It says that retaining controls on electronic transfers and sharing of technical data is an important part of export controls in a broader sense and especially in the context of increasing 3D printing and additive manufacturing capabilities.