It seems like Yahoo is a little bit worried about possible exploitation. From the Terms of Use: 2.3. You may derive and publish summaries, analyses and interpr

It seems like Yahoo is a little bit worried about possible exploitation. From the Terms of Use: 2.3. You may derive and publish summaries, analyses and interpretations of the Data, but only in a manner where it is impossible to reconstruct the Data from the publication. Small excerpts of the Data may be displayed to others or published in a scientific or technical context, solely for the purpose of describing your research and related issues and not for any commercial or anti-competitive purpose. Unless Yahoo! expressly requests no attribution, all publications resulting from research carried out using the Data must display an attribution to Yahoo!. This attribution must reference "Yahoo! Webscope,” the web address http://webscope.sandbox.yahoo.com http://webscope.sandbox.yahoo.com, and the name of the specific dataset used, including version number, if applicable. This attribution should preferably appear among the bibliographic citations in the publication. If Yahoo! expressly requests no attribution, you agree not to mention Yahoo! in connection with the Data. Yahoo! invites you to provide a copy your publication to Yahoo!. This[0] seem fairly restrictive, considering that I can just crawl flickr and get all that data and more, were I so inclined. Also kinda interesting, in this passage and the rest of the TOU: they repeatedly use `"` interchangeably with actual quotation marks ("), suggesting that nobody at Yahoo has proofread their own live TOU. Still, the dataset seems really cool. [0] ...and other parts of the agreement, but I don't want to spoil it for you, nor post its entirety as a comment.