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Comment by necubi | Hacker News Reader

There seems to be a lot of misinformation flying around. Here's [0] Google's support doc that clears up some of it.

The most important part is at the end:

"In some cases, senders may be able to know whether an individual has opened a message with unique image links. As always, Gmail scans every message for suspicious content and if Gmail considers a sender or message potentially suspicious, images won’t be displayed and you’ll be asked whether you want to see the images."

So Google apparently does not see read receipts as a problem. The privacy and security protections are about preventing other information (like ip, browser headers, cookies) from leaking, rather than read notifications.

If you care about maintaining your privacy, I would recommend disabling the new functionality.

[0] https://support.google.com/mail/answer/145919?hl=en&ctx=mail

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Wow, I'm amazed by this. I was convinced that Google wouldn't have rolled out this new feature unless they had a way to avoid this sort of tracking. Isn't this exactly the privacy issue that led clients to adopt "Don't display images automatically by default" in the first place?

(Why wouldn't they let users combine this behavior with the old one? That is, don't display images by default, but if you choose to display them anyway, get the file from Google's proxy server.)

They do combine those behaviors. The proxying is on for everybody, regardless of whether you disable showing images automatically.

Actually, the most serious reason (and the reason why not displaying images was introduced in the first place for unknown senders) was the potential for exploits triggered via embedded images, e.g. http://news.netcraft.com/archives/2004/09/17/exploit_for_mic... or even just using it to bypass firewalls by having someone inside an organization execute a GET request (via img src=) from a browser inside the firewall. (P.S. This is one reason why write operations should always use POST...)

I thought "Don't display images automatically by default" was a response to porn images.

These two statements of yours seem at odds with each other:

"The privacy and security protections are about preventing other information (like ip, browser headers, cookies) from leaking, rather than read notifications."

"If you care about maintaining your privacy, I would recommend disabling the new functionality."

"Disabling the new functionality" refers to maintaing the old behavior of hiding images by default. This means that you're leaking nothing unless you explicitly decide to. This does not appear to disable the proxying, though, so you're still covered by these additional protections when you do explicitly show images.

What he meant is to disable the new functionality and revert to the default blocking of any images, which is definitely the most privacy-preserving option.

The new functionality seems to by default enable read notifications as Google seems to load all images by default. Unless that's false. Then it should have no impact on privacy.

The options are "Display images via this proxy mode that still leaks some privacy" and "don't display images. 100% privacy".

When I just tried disabling it, the images that were displayed after I clicked 'Display Images Below' all still went through the proxy.

It's a delivery receipt, not a read receipt. Delivery receipts already exist, in the sense that Google will tell (non-suspicious) senders if the message is deliverable.

Gmail is pre-fetching the image as part of the message.

I have an inbox crammed with unread messages. I okayed the new image behavior, checked a few messages and noticed how google loaded images without asking me, which is fine, I did agree on that.

I then reverted back to the old image settings but when I open unread messages now, they also have their images loaded automatically and without asking me.

Either the "revert back to original settings" are broken, or the caching of images is done when I enter my inbox, for all unread messages.

I'm not yet seeing this option available in my account. :(

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