Metaphors matter. The search and data mining platforms I helped develop, Lantern and Arclight, take their names from light sources. The names derive from historic film technologies, and they also riff on Apache Solr, the open-source search index that powers both platforms. However, the names of Lantern and Arclight are first and foremost meant to evoke the idea of shining light on something we previously had difficulty seeing. There is no doubt that these platforms – and the nearly two-million-page collection of the Media History Digital Library (MHDL) that they search – have illuminated sources that film historians had previously neglected and enabled a new scale for running research queries. However, I increasingly think about the other side of the light metaphor – the shadows that rapid search power and a sense of digital abundance may cast on other sources. The MHDL, for example, has two especially deep shadows. Due to intellectual property constraints, books and periodicals that were published after 1964 and/or outside of the United States are underrepresented in the collection.