"Data democratization" movements try to make data, and especially government-held data, publicly available and accessible. A growing number of technological efforts are devoted to such efforts and especially the accessibility part. One such effort is by data visualization companies. A recent trend is to offer a free version (or at least free for some period) that is based on sharing your visualization and/or data to the Web. The "and/or" here is important, because in some cases you cannot share your data, but you would like to share the visualizations with the world. This is what I call "data liberation via visualization". This is the case with proprietary data, and often even if I'd love to make data publicly available, I am not allowed to do so by binding contracts.
As part of a "data liberation via visualization" initiative, I went in search of a good free solution for disseminating interactive visualization dashboards while protecting the actual data. Two main free viz players in the market are TIBCO Spotfire Silver (free 1-year license Personal version), and Tableau Public (free). Both allow *only* public posting of your visualizations (if you want to save visualizations privately you must get the paid versions). That's fine. However, public posting of visualizations with these tools comes with a download button that make your data public as well.
I then tried MicroStrategy Cloud Personal (free Beta version), which does allow public (and private!) posting of visualizations and does not provide a download button. Of course, in order to make visualizations public, the data must sit on a server that can be reached from the visualization. All the free public-posting tools keep your data on the company's servers, so you must trust the company to protect the confidentiality and safety of your data. MicroStrategy uses a technology where the company itself cannot download your data (your Excel sheet is converted to in-memory cubes that are stored on the server). Unfortunately, the tool lacks the ability to create dashboards with multiple charts (combining multiple charts into a fully-linked interactive view).
Speaking of features, Tableau Public is the only one that has full-fledged functionality like its cousin paid tools. Spotfire Silver Personal is stripped from highly useful charts such as scatterplots and boxplots. MicroStrategy Cloud Personal lacks multi-view dashboards and for now accepts only Excel files as input.