Yes, the alpha version (what we just launched) only works on third-party cookies, so the heuristic blocking algorithm doesn't do anything if you block 3rd party cookies entirely. We plan to add detection of other tracking methods (Flash cookies, local storage, fingerprinting, etc.) as time goes on. More info in the Firefox version's README: https://github.com/EFForg/privacybadgerfirefox/blob/eb1055c4...