This dataset is obsolete because the Twitter pHashes were incompatible with all the other pHashes in the dataset due to a version mismatch of the ImageHash Python library. Please download the updated dataset here: https://zenodo.org/record/3699670 This dataset was collected with research funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No 691025. The publication on which this dataset was used is: "On the Origins of Memes by Means of Fringe Web Communities". Savvas Zannettou, Tristan Caulfield, Jeremy Blackburn, Emiliano De Cristofaro, Michael Sirivianos, Gianluca Stringhini, and Guillermo Suarez-Tangil. ACM Internet Measurement Conference (IMC), 2018., DOI: https://doi.org/10.5281/zenodo.1323551 The dataset consists of all the URLs and phashes for images from Twitter, Reddit, 4chan's /pol/, and Gab posted between July 2016 and end of July 2017. The code related to this research can be found here: https://github.com/memespaper/memes_pipeline, or here: https://doi.org/ 10.5281/zenodo.1463050 Presentation available here: https://doi.org/10.5281/zenodo.1477082