2.1. What information might this feature expose to Web sites or other parties, and for what purposes is that exposure necessary?
No new information is exposed, except: If a party within the browsing context is engaged in self-capture using pre-existing means, and a third party within the same browsing context had minted a token and passed it to the first party, then the first party can learn of when a certain region in the document goes in/out of the viewport, by listening to the mute track's mute events.
2.2. Do features in your specification expose the minimum amount of information necessary to enable their intended uses?
Yes.
2.3. How do the features in your specification deal with personal information, personally-identifiable information (PII), or information derived from them?
Not applicable.
Not applicable.
2.5. Do the features in your specification introduce new state for an origin that persists across browsing sessions?
No.
2.6. Do the features in your specification expose information about the underlying platform to origins?
No.
No.
No.
No.
No.
2.11. Do features in this specification allow an origin some measure of control over a user agent’s native UI?
No.
This feature allows a website to mint tokens called CropTarget. These are opaque interfaces which are only meaningful within their browsing context. They do not outlive the browsing session. The party minting the tokens may transfer them to trusted third parties within the browsing context. The only use these tokens have, is to allow stripping information from a video stream by cropping it.
2.13. How does this specification distinguish between behavior in first-party and third-party contexts?
Not applicable.
2.14. How do the features in this specification work in the context of a browser’s Private Browsing or Incognito mode?
The feature does not behave in any special way in this mode. Note that this feature is an extension of the Screen Capture, that allows stripping away information previously gained through that other feature. If Screen Capture should behave differently in Private Browsing or Incognito modes, is an orthogonal question.
2.15. Does this specification have both "Security Considerations" and "Privacy Considerations" sections?
No. This feature is deemed security- and privacy-trivial.
No.
Not applicable.
Nothing more is presently required.