Since the mid-2000s, some US and British news organizations have hired programmers to design data-driven news projects within the newsroom. But how does the rise of these "programmer-journalists," armed with their skills and technical artifacts, really affect the way journalism can contribute to the public good? Based on an empirical study in Chicago, we show in this article that although they have built on previous historical developments, these programmer-journalists have also partly challenged the epistemology conveyed by the computer-assisted reporting tradition in the US, grounded in the assumption that data can help journalists to set the political agenda through the disclosure of public issues. Involved in open source communities and open government advocacy, these programmers and their technical artifacts have conveyed challenging epistemological propositions that have been highly controversial in the journalism community.