Regulating intelligence services is a challenge for modern societies worldwide. Their very modus operandi relies on tight secrecy protocols for the information gathered, internationally and domestically. Evolving surveillance techniques include exploiting the vulnerabilities of digital services, dealing on unregulated surveillance markets, and developing tailored tools. Theoretically, these actions aim at the public interest by, for instance, anticipating terrorist attacks or dismantling pedophilia networks. Nevertheless, they are increasingly used to surveil civil society without proper and demonstrated necessity or proportionality. Given the demand for increased transparency and accountability for intelligence agencies, especially when using hacking technologies, what institutional design and civic participation avenues for oversight may be proposed? How can (existing and yet-to-exist) institutions improve democratic external oversight activities in this realm? Through a comparison of Germany’s and Brazil’s legal frameworks and institutional ecosystems, the paper critically explores the meaning of “democratic oversight” of intelligence agencies, specifically observing oversight models for hacking operations. Looking at previous contributions by intelligence studies scholars in these countries and globally, the paper offers a critical-comparative analysis of institutional and political architectures to assess the levels of democratic participation. On this basis, it makes recommendations for both countries, which can be appropriated by external intelligence oversight bodies.