Re: [Page Visibility] Spec -- privacy concern

I'm not entirely certain the answer to your question... but I'd submit that 
if such functionality exists and is truly reliable and represents the same 
visible/hidden states we're discussion, then on principle why are we 
creating a new event/state property for something that already exists?

If they aren't the same thing, then `blur`/etc must necessarily be a subset 
of the proposed new functionality, so it by definition introduces new 
potential privacy leaks.


From: "Sreeram Ramachandran" <>
Sent: Saturday, May 14, 2011 2:06 AM
To: "Kyle Simpson" <>
Cc: <>
Subject: Re: [Page Visibility] Spec -- privacy concern

> On Fri, May 13, 2011 at 16:50, Kyle Simpson <> wrote:
>> One major privacy concern I (and others I chatted with on Mozilla's
>> #developers IRC) have is that third-party scripts (like ad providers, 
>> etc)
>> would be able to monitor this type of data (page visibility) and gain
>> valuable (to them!) information which a user might not want them to have,
>> such as how long I stay viewing a page, etc.
> Doesn't this privacy concern also apply to other existing mechanisms,
> such as window.onblur/onfocus/onpageshow/onpagehide? It's not clear to
> me that the visibility API introduces additional privacy-violating
> capabilities on top of those.

Received on Saturday, 14 May 2011 00:45:18 UTC