The data sharing was so deep that even Facebook's business partners were surprised by it: Spotify said it was unaware of this special access while Netflix claims it never checked people's private messages on Facebook nor did it ever "ask for the ability to do so." Apple, meanwhile, was white-listed to view users' phone numbers and calendar entries, but it said it was not aware of this special access. In a blog post last night, titled "Let's Clear Up a Few Things About Facebook's Partners," Facebook said these data-sharing partnerships were about two things:

"First, people could access their Facebook accounts or specific Facebook features on devices and platforms built by other companies like Apple, Amazon, Blackberry and Yahoo. These are known as integration partners. Second, people could have more social experiences -- like seeing recommendations from their Facebook friends -- on other popular apps and websites, like Netflix, The New York Times, Pandora and Spotify."

The biggest issue with Facebook, which hasn't responded to our request for comment, is that it always waits until after a bombshell to clarify its policies -- that's how it got into this mess to begin with. And if we were already questioning why anyone should trust Facebook with their data, especially after what happened with Cambridge Analytica, this latest story is the clearest example yet of why people shouldn't. That's saying a lot, too, considering that it seems like every week there's new information about how Facebook mishandles user data.

This is also going to draw additional questions from lawmakers in the US, who are already deeply concerned with how Facebook operates and are pushing for stronger federal oversight. Under the 2011 Federal Trade Commission consent decree, Facebook agreed to get authorization from users before sharing any of their data as well as to notify them in the event of any unauthorized access. Facebook says that "none of these partnerships or features gave companies access to information without people's permission."

But while users may have willingly connected their Facebook account with Spotify or Netflix, that doesn't mean they knew those apps were going to be able to read their private messages. Even if Facebook's partners claim they didn't take advantage of such special access, the company needs to do a better job of making sure its policies and terms of service are easier for everyone to understand.