transparency:

The majority of our domestic requests consisted of subpoenas, followed by search warrants. As shown above, Tumblr produced blog content in response to 31% of domestic requests, account data in response to 84% of domestic requests, and nothing at all in response to 16% of domestic requests. In cases where no content or data was produced, the requests may have been withdrawn, or were defective, or we may have objected to the requests on legal grounds.