Re: Request Privacy review of HTML5.3

Hi Privacy-interested colleagues,

We talked briefly about the HTML 5.3 spec at our call this month and the prospect of providing privacy review or feedback by the requested deadline of May 25th (GDPR Day! tomorrow!). I'm trying to work through the changes that seem most relevant to privacy.

While I'm working on that, I have written up some comments on the a ping attribute which has resurfaced in this draft. Comments are included below -- I would welcome any feedback before we share directly with the HTML WG. I can just provide comments on an individual basis since we're very close to the deadline and I don't expect to be able to gather the consensus of everyone who might participate in this Interest Group, but I still wanted to have a chance to get your review if you happen to have additional ideas.

Cheers,
Nick

---

Via https://github.com/w3c/html/issues/369 <https://github.com/w3c/html/issues/369> it looks like the ping attribute has re-appeared.

When this was discussed in the past, I believe privacy concerns were specifically cited as a reason not to include this in the updated HTML5 spec, but it seems to have gone ahead on this draft, based on increased implementation experience.

When it was discussed with the Privacy Interest Group in April 2017, a specific comment was noted:
> Note that if we have a requirement that user agents clarify to the user that the link will ping other sites, we need to test whether that happens in real implementations.

That concern stands.

Here is the relevant text from the spec (present in both WHATWG HTML and HTML 5.3 WD):
> user agents should make it clear to the user that following the hyperlink will also cause secondary requests to be sent in the background.

Has anyone tested the real implementations to verify that user agents clarify to the user that the link will also cause secondary requests to be sent in the background? In my quick checks on current versions of Chrome and Safari on Mac OS clicking on links from a google.com <http://google.com/> search results page, I couldn't determine that secondary requests were being sent in the background short of opening the network inspector and observing HTTP POST requests. I trust that we don't believe that is "clear to the user". (The spec includes an example suggesting use of a tooltip; I'm not sure that's very clear either, but I haven't seen that in existing implementations anyway.) Do others have tests/screenshots/etc. documenting implementations that fulfill this requirement?

Indeed, the question of implementing the clarity requirement was raised in 2007, with the suggestion that if sufficient UI wasn't being implemented within a year, then the feature should be revisited:
https://lists.w3.org/Archives/Public/public-html/2007Nov/0055.html <https://lists.w3.org/Archives/Public/public-html/2007Nov/0055.html>

If there haven't been compliant implementations developed in the past 10 or 11 years, then I question whether there is sufficient implementation experience or whether implementers believe that feasible UI is possible to meet that requirement.

I believe there are good motivations for the ping attribute feature in a way that could help user privacy. However, I think we need to be cautious about a feature where the privacy UI hasn't been developed for this long. Indeed, this might be a step backward in transparency for end users, who in some cases now can no longer use the status bar to observe that they're being redirected through a tracking link, and might conclude that tracking isn't happening, that they're navigating to a site by clicking a link without any background communications. In neither browser I tested could I find a setting to disable sending these background requests, as was proposed as an advantage of the feature.

If implementers believe that the clarity requirement is actually unnecessary and that it's still better for user privacy, that would be a separate question to discuss. That approach might better match the reality of implementations, but I'm not sure what the privacy advantage is if users have neither awareness nor control of background tracking requests.

> On Apr 26, 2018, at 5:31 AM, Léonie Watson <tink@tink.uk> wrote:
> 
> Hello Privacy,
> 
> We would welcome your review of HTML5.3 [1].
> 
> To help make your review easier, we have produced a changelog that contains all substantive changes made since HTML5.2 [2]. Please also note that there are features marked "at risk", documented in the Status.
> 
> If there are any issues arising from your review, please file them on the HTML Github repo [3], and apply the "wide review" and "privacy" labels to each issue. This will help us track your issues and ensure we respond accordingly.
> 
> We would appreciate your feedback no later than Friday 25th May 2018. Thank you.
> 
> Léonie on behalf of the HTML Editors and WebPlat Chairs.
> [1] https://www.w3.org/TR/html53/
> [2] https://www.w3.org/TR/html53/changes.html#changes
> [3] https://github.com/w3c/html/issues/new/
> 
> --
> @LeonieWatson @tink@toot.cafe Carpe diem
>