Facebook privacy issue: Google search reveals email addresses in Facebook

http://corywatilo.com/a-real-facebook-privacy-issue-email-addresses

by a4agarwal • 16 years ago

141 65 16 years ago

a4agarwal• 16 years ago

Google is indexing Facebook's "Opt out of emails from Facebook" page for email addresses that were submitted using the "Find a friend" feature.

I checked out the Google site and saw a few addresses in the format name.secret@blogger.com, which indicates these are the SECRET email addresses people use to post to their blogger sites. Pretty bad.

Freebytes• 16 years ago

I wonder why we are seeing more issues about Facebook privacy issues recently. Is it because the coverage of this has made people start questioning their policies and looking into things that have not been researched or is Facebook becoming more lacksidasical about privacy as time passes? Or, have these things been said a lot in the past, and we are just now realizing the plethora of complaints?

corywatilo6• 16 years ago

Most of the recent stories are people whining about Facebook's policies and complexity of privacy settings.

This is an actual privacy bug.

ambition• 16 years ago

Did you report it to Facebook before publicizing it?

andreyf• 16 years ago

It's a self-reinforcing problem: I imagine most startups that grow as fast as Facebook don't have a perfectly engineered architecture, simply because they're desperately optimizing their products for time-to-market. When the "Facebook has security and privacy issues, and might be evil" meme gets around, people start looking for more weaknesses and quickly find them. From my limited experience in startups, none would be immune to such scrutiny.

Facebook is at a very challenging point right now: they need strong short-term PR, very fast patching up of issues as they arise, cleaning out the tech debt they acquired in their youth, and most importantly, battling off the fierce competitors of all stripes and colors: from Google to Twitter to foursquare. Will they be able to do it? Based mostly on their ability to capture as large a market as they did and their fast attention to issues as they arise, I think so: as long as they don't piss off their users enough for them to leave en masse (and they haven't - most of their users don't care about the privacy issues we go crazy over), they just need to hold on and keep doing more or less what they've been doing.

tokenadult• 16 years ago

I imagine most startups that grow as fast as Facebook don't have a perfectly engineered architecture, simply because they're desperately optimizing their products for time-to-market. When the "Facebook has security and privacy issues, and might be evil" meme gets around, people start looking for more weaknesses and quickly find them.

This sounds like by far the most likely explanation for most of the Facebook problems. The Facebook non-system has become sufficiently internally complicated that no one person understands it anymore, which makes it easy to overlook security weaknesses. The systematic attempts to "share" information on the part of Facebook's leadership have been quite annoying, and have made me MUCH more circumspect in my Facebook behavior, but all the rest of this is just sheer inadvertence.

sounddust6• 16 years ago

Because there have been a lot of legitimate Facebook privacy issues recently?

When the world's second largest site allows you to monitor the private chats of 400 million people - when it leaks your IP address to other people via e-mail for no reason - and now when it's leaking people's e-mail, then it's a big deal.

That's not even taking into consideration the privacy issues that were not bugs.

natrius5• 16 years ago

Facebook leaked your IP people you communicated with, not that IPs are that sensitive in the first place. It wasn't a big deal.

sounddust6• 16 years ago

So, how did Google become aware of the existence of these URLs in the first place? I seriously doubt they're linked from another Facebook page.

Is Google harvesting links from secure pages using their toolbar or something? Are people's personal mails leaking through other means?

I noticed that a few of them are indexed by Google because someone decided to reprint the email - URLs and all - to their blog. But that's a rare exception,and obviously not the case with the author of the article.

tcoxon2• 16 years ago

It's simple: Google has access to the referrer URL when you go onto their website. It's well known that they index these URLs.

If you go from that Facebook page straight to Google, it'll get indexed.

sounddust6• 16 years ago

In what situation would the HTTP referrer header report Google when clicking away from a Facebook link? Not only is there no Google search field on Facebook, but Facebook also reroutes links through an intermediary page in order to hide the actual referring page.

noelchurchill• 16 years ago

Google has multiple ways of indexing, and following links is only one of them.

I suspect Google found these pages by scanning the directory structure of facebook, indexing all pages in these subdirectorys, and finding more subdirectories to drill in to.

eli2• 16 years ago

I think (though I'm too lazy to confirm) that the Google Toolbar browser plugin also reports URLs back to Google

loboman• 16 years ago

And how do they do that (scan a web site directory tree) without following links? You are describing the same "following links" procedure I think.

Maybe somebody accessed those pages using the Google toolbar, in that case Google could have known about those pages even if they were not linked from any other pages elsewhere.

petewarden• 16 years ago

If you look at http://facebook.com/robots.txt there's actually a sitemap. It's protected, and may well not contain these pages, but I have heard that Google and other privileged partners have access to it.

gojomo• 16 years ago

With Google and Facebook working together as a 1-2 punch, I'm confident we can squash the last vestiges of privacy very soon.

corywatilo6• 16 years ago

Just wait until Obama buys them. Or just decides to takes them over.

DanBlake• 16 years ago

Isnt it a bit more concerning that we can modify these peoples settings by clicking the links? (at least it appears we can) I have not checked but there may be a way to modify the url string to view anyones email (sample URL taken from that guys post below)

http://www.facebook.com/o.php?k=16531b&u=100001103986041... (warning- clicking this link will log you out of facebook with no prompt)

Or, perhaps a way to take the authentication hash + mid hash's from above to perform another function on someone elses account. (like changing the email, or changing privacy settings)

what4• 16 years ago

It would probably be near impossible to view an email for a specific account or any random account. The mid value can be removed entirely (it seems) and I'm guessing u is a userid(?), but you would have to figure out the value for k that matches the id.

GrandMasterBirt2• 16 years ago

You are on to something here. A link that auto logs u out. Can we embed this link in a post on facebook, therefore auto logging people out just by visiting their wall? It would be the ultimate annoyance.

whatwhatwhat2• 16 years ago

I just did this and it works.

If a user has an application such as advanced wall or super wall you can use the following to log people out.

The worst part is that if you just try to login again at the prompt (instead of going to facebook.com) you get redirected back to the post and logged out again in a loop.

evancaine2• 16 years ago

this was the last straw for me. I just requested that FB delete my account

ScottWhigham• 16 years ago

And the lovely newbies here at HN downvote you for that. Sheesh - I don't get what's happened here over the past 6-9 months.

houseabsolute2• 16 years ago

After you read enough "this is the last straw" comments about Facebook, it gets old.

blakeross5• 16 years ago

Hey all,

I work at Facebook, but this is not an official media statement.

This doesn't appear to be a Facebook bug that leaks anyone's private email address. It appears that all the examples indexed in Google exist in Google because they were already published publicly on other Internet sites. We're committing a fix right now to stop indexing this page in Google, but even that wouldn't prevent email addresses from being published because it appears that users are already republishing their addresses in other non-Facebook venues.

For example, if you see http://www.facebook.com/o.php?k=afc4a7&u=1018862530&... in isolation, it appears to be divulging private information.

However, the original Facebook email that links to that page and contains the user's email address was republished publicly on a mailing list archive by the owner of the email address: http://games.dir.groups.yahoo.com/group/Living_Greyhawk/mess...

Does anyone see an example where this is not the case that constitutes a privacy leak?

Blake Ross

corywatilo6• 16 years ago

Blake,

Thanks for following up. My personal email address is indexed, but is nowhere else on the internet. Shoot me an email at hi@corywatilo.com and I'll give you the address.

blakeross5• 16 years ago

Hi Cory -

Can you see my response below regarding Posterous?

Also, it does appear that your email address is available on the Internet, e.g. http://groups.google.com/groups/profile?enc_user=nBw3lBQAAAA...

Thanks, Blake

blakeross5• 16 years ago

Furthermore, the author of the blog post in question republished his own Facebook email on http://corywatilo.com/reminder-cory-invited-you-to-join-face...

Although his email opt-out link has been edited out of that email (see "please clic to unsubscribe." at the bottom), it appears that the email was originally published to Posterous in its entirety via his iPhone and then edited later, after it was picked up by Google.

(Update: The author of the original blog post acknowledges this below.)

sounddust6• 16 years ago

Good point. That blog post has a link "to sign up for facebook", and when you click on it, it reveals the gmail address of the user (which is something @gmail.com). At least that answers the question of how Google found it.

corywatilo6• 16 years ago

This is possible. +1 Blake

Would be nice for FB to exclude that page from getting indexed though.

jpeterson• 16 years ago

Sorry, but it is a Facebook bug. Facebook could've easily instructed google not to index these pages.

blakeross5• 16 years ago

It wouldn't have mattered. The user republished a Facebook email on a non-Facebook venue (such as a public mailing list archive), thus exposing their email address. See, for instance, http://groups.yahoo.com/group/salemwhitemagic/message/89

corywatilo6• 16 years ago

Maybe a better term would be oversight.

luckyland• 16 years ago

Listen, this isn't the point.

The point is that Facebook should be responsible for protecting their own indexing vectors.

Plain and simple.

GrandMasterBirt2• 16 years ago

It gets funnier... This poor sob just got their email revealed when i searched for

"Email Opt-Out | Facebook"

I can also disable facebook emails for them:

http://www.facebook.com/o.php?u=1187719938&k=5fcf21

volomike• 16 years ago

Oh that's just crazy. I just clicked that link but didn't click Confirm because ?u= is someone else's user ID.

What's sad is that because it's numeric, you can run down a whole list of IDs, opting people out or in.

So what's k stand for, crc32() or something like that on the u parameter?

bruceboughton• 16 years ago

You should never expose internal incremental user ids in URLs like these. Have a combination of guids that links to the user id in your database.

bluishgreen2• 16 years ago

Scribd! I am seeing my email ID being published as the title for my scribd account page.

bluishgreen2• 16 years ago

umm, May I know why I am being down voted. Just Curious.

drivebyacct• 16 years ago

If your information is PUBLIC, what the HELL do you expect? There are so many good reasons to be irritated with Facebook's privacy debacle. This is not one of them.

Matt_Cutts• 16 years ago

I can debunk the misconception that Google somehow crawled "private" or Gmail content to discover these links. How can I prove it? Because Yahoo crawled these pages too. Here's a screenshot I took of Yahoo returning similar pages: http://www.mattcutts.com/images/yahoo-facebook-leak.png including a Gmail address. Yahoo clearly didn't discover that content via Gmail--it found it via public links on the public web. That's how Google found these pages too.

Facebook privacy issue: Google search reveals email addresses in Facebook

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