-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Hi, mnot has already heard the following concerns from us at CDT about this spec, but we want to make sure that these are part of the IETF last call comment record. * The "Safe" preference is not only a preference but a signal. It signals user vulnerability; when activated, the header would signal a user's potentially vulnerable status not only to site operators who intend to reply in good faith, but to those that will operate in bad faith and also to every intermediary on-path that could read the preference request. Details about an Internet user's vulnerabilities should be treated as sensitive information. A broadcast signal that advertises a user's content preferences or restrictions can signal her youth, cognitive ability, relative media illiteracy, technological inexperience, or another potential vulnerable status. Because of the risk that this information could be used to exploit immature or inexperienced users, CDT generally cautions against widespread identification of user vulnerability. Obviously, sending such a preference inside an encrypted connection removes concerns about on-path observers, but not the more general concern with bad faith endpoints or other embedded endpoints that may have other interests (e.g., advertisers on a service may use this signal to profile vulnerable populations). * Further, the ability for other intermediaries with access to the request stream to insert the preference, potentially without notice to the user, means that users may not even be aware that they are broadcasting potentially sensitive information about themselves, thus limiting their ability to take self-protective measures against potential abuse. * As many of the comments in Last Call have identified, "Safe" content in this specification is undefined. Because the proposal (necessarily) lacks a definition of "safe", it is unlikely to be useful to parents/guardians/users. The lack of definition will produce diverse and conflicting interpretations from content hosts and providers, which can mislead users and their guardians, and may invite abuse and confusion. The absence of guidance to websites wishing to participate in "safe" content delivery will lead to varied and sometimes contradictory results. This could sow confusion and potential conflict among participating platforms and website operators, and undermine the utility of the specification. Moreover, users and their parents will have diverse expectations about "safe" content. These expectations will vary considerably with users' age, as well as parent/guardians' cultural backgrounds. Without a common understanding of what qualifies as "safe" content, the expectations of users and their parent/guardians are likely to be frustrated. Of course, it is far outside the scope of a technical specification to define a content-label like "safe". But because a standardized definition of "safe" content is unattainable, the specification will have limited use as a tool for empowering parents to regulate and guide their children's Internet use. - -- Joseph Lorenzo Hall Chief Technologist Center for Democracy & Technology 1634 I ST NW STE 1100 Washington DC 20006-4011 (p) 202-407-8825 (f) 202-637-0968 joe@xxxxxxx PGP: https://josephhall.org/gpg-key fingerprint: 3CA2 8D7B 9F6D DBD3 4B10 1607 5F86 6987 40A9 A871 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (Darwin) iQIcBAEBCAAGBQJUZOgJAAoJEF+GaYdAqahxzogP/A971Lf1c4weSTq1XtCUVna/ N8+ezBEd1qJ0FaSggPQeZi6Ri6TkqpNmyLUdgZ85oACS1QX37oOCS0vGoKXODRKq NJ15FloP0hQgPhRFjCEIFPg4z/YUJiATtBU7+QQTMPvJbV9vA/tK5PSkv5qLXGI0 W4sc01Yhh4K4OtE4BN5Lj+zedNaBrihKtB/c3oGLZt20sNhn5VX1XzmeuTktTV39 IkuoBfcV8/00gq//nJ1f5UPm7Z3GfhCeuTFhfT6DXTC9PTHhYxLUgKglARw+1ynA P2mRdqjxkpwNBVeeS81Xeg+G6RJ3IMZ5/HCftK9GuUbXz5MSBOQmSzY2hhHEQMdc +LZHHFx/eKTpGehmgYx+xv85pdqaUlFZti9zOAlmkYvI+Mq3AjZQfSkmtGV5OlxQ rcfaTWAfNNeVa8C6fNfYo2bSFSAqSUPKWY2s7khY3m8nbugiitb60c57W1FnNFnX pDPJIjAJv37Ob84kZvQbKXXaQwSQSvSnLtaUS55Y/yvpR7goVtxBRHSaGw1sY5qO XIeAeLRSCHjmyc8yr/v21EhLvPVu1ZSgi665mTkQG/mxkmq7MSd3edQz8s4RGfIY 5Vk0dQqCayORynF97Z6i+ylCTqPbSlANDBXuaByyQU1nnnFfV2K5Xo8lgpe0T9kV 3WIlRxdvbOAabkYgjE6G =4UPs -----END PGP SIGNATURE-----