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Gmail blows up e-mail marketing by caching all images on Google servers

arstechnica.com

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Re: Gmail blows up e-mail marketing by caching all images on Google servers

#61

Post by YourSexyMama »

So there is something I'm not seeing this being discussed anywhere. What about the idea of only storing one image for any and all recipients? Yes I know that the file name is changed based on recipient to try and track the users viewing of the image. But a simple md5sum of the file will indicate that it is potentially the same file as others being cached. Google would only need to store the references and the one file. Thus, the first person to view the file (per maximum cached time-frame) would indicate a viewing of the file, but subsequent users would never be identified as having viewed the file.

I recognize that there are a couple potential downfalls to this thought. 1) The time/processing it takes to determine the md5 could be problematic on such a large scale. 2) I have no idea how easy it is to change an image to be unique for each user.

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#62

Post by Nacraile »

codeflo wrote: post #44
surrealize wrote: post #39

Earlier quoted context omitted.

Google could retrieve and cache a random sample of the images and hash them. Then they could note which image links go to the same images. And they could identify image links by noting that a bunch of emails have the same structure except for one image link that's different for every recipient. So I think they actually could take a pretty good stab a deduping images with unique tracking URLs. It might not be perfect,…

Easy: Make the "Dear " part of the email an image. Boom, deduplication fooled. (Also, they don't currently seem to do anything like you're suggesting.)

What if google just immediately fetches images for all received messages, regardless of deliverability? They can dedupe wherever possible, but the sender still ends up with no information about whether the message was delivered, much less read.

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#63

Post by petercooper »

slg wrote: post #34
trevyn wrote: post #28

Earlier quoted context omitted.

> Google has no way to know that all of those point to the same image. Try again. :)

Yeah, I am not sure where the original claim is coming from. It isn't that hard for Google to simply follow the links and compare the files as part of the caching process. So unless marketers start customizing the images in addition to the links, there isn't any reason why Google can't cache the images together. And even if marketers do start customizing images, hasn't Google gotten pretty good at comparing very simi…

And even if marketers do start customizing images, hasn't Google gotten pretty good at comparing very similar files?

For image tracking pixels, I'd just start returning PNGs of random dimensions with completely random pixel data. Ta-da, unique images that aren't similar at all (unless they wanna start doing wavelet transforms or something).

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#64

Post by ben0x539 »

jessaustin wrote: post #58
untog wrote: post #47

Earlier quoted context omitted.

hasn't Google gotten pretty good at comparing very similar files? Sure, but they'd have to download the file first. At which point the tracking has succeeded.

...the tracking has succeeded. Succeeded in what, confirming that Google is still in operation? Please note that Google doesn't even have to confirm the receiving email address is valid in order to get the image.

"early tests indicate that they don't actually do that, waiting for the user to click the email to make the request."

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#65

Post by petercooper »

seiji wrote: post #17
kevrone wrote: post #2

Holy crap. If I'm reading this right, this basically destroys all pixel tracking, so no more email open stats, no nothing.

You have no right to know what your users are doing after you send them a message. The privacy invading "tracking pixels" shouldn't exist in the first place.

Why shouldn't content providers be free to monitor usage if it's legal and easy to do? Would you next start to argue SaaS providers shouldn't have any Web server logs at all since it's a way of "tracking" users?

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#66

Post by necubi »

cloudwalking wrote: post #38
necubi wrote: post #19

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…

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.

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#67

Post by ben0x539 »

cloudwalking wrote: post #38
necubi wrote: post #19

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…

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."

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

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#68

Post by AznHisoka »

nanidin wrote: post #48
coffeecheque wrote: post #3

Longer discussion here: https://news.ycombinator.com/item?id=6895606

Hmm - so we can flood Google's cache by sending an email full of links to procedurally generated images?

you'd flood your email server before you'd flood Google's cache.

Re: Gmail blows up e-mail marketing by caching all images on Google servers

#70

Post by nchuhoai »

cloudwalking wrote: post #38
necubi wrote: post #19

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…

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."

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.

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