If someone curiously inquired me on this type of information I’d tell them without giving a second thought.
This is the difference between you and people who care about their privacy, then. I would happily talk about that to someone I trusted, but not a random person on the street, and certainly not someone whose interests I know don’t align with mine, which is mostly true of every company on Earth. Not to mention that any of these companies could be subpoenaed for this information at any time, which would be an issue if the law changed to make something I do illegal.
Good timing on their part; I just rejoined Tumblr in order to reconnect with some friends and this is just the push I needed to delete my account again.