I used this code to scrape three databases for information about non-owner occupied property in Baltimore, in hopes of identifying entities which own a large number of vacant properties. Check out the blog post for a full explanation and important caveats.
All of the data have been published to https://github.com/subelsky/baltimore_property/downloads.
If you'd like to explore the data on your own I recommend loading
into Google Refine.
Licensed as Creative Commons. See LICENSE file for details.