decoding flickr picture urls
A couple of blogs that I read are run by people who use a pseudonym. I can certainly understand why they’d want to remain anonymous, the internets being a dangerous place and so on. I do the same obviously (no, my parents didn’t actually name me “drac” although that would have been cool too). I can see a difference in my approach and theirs, if only because I use a pseudonym to prevent embarassing Google powered collisions between my real life and the blogger world. My real name is out there for anyone who knows where to look. However, these people actually go to extreme lengths to edit references to their names (in comments) and take seemingly elaborate precautions to prevent accidental disclosures of their identity.
Unfortunately, they also embed photos from Flickr in their blog. As a thought exercise, I wanted to see if this practice was a good idea or not, in light of their need for anonymity. So, I wanted to see if I could go from a static.flickr.com URL (which is commonly used to link photos uploaded to Flickr) to a Flickr user account. Stalker wannabes, please start your engines.
First place to look was the excellent Flickr API documentation. Therein, I discovered this guide to Flickr URLs. As can be seen, a static.flickr.com URL is actually composed of several parts: the server id, the photo id, the secret key and the size of the photo. Ok. I’ve now figured out the photo ID of the photograph I want to track down.
Flickr photo IDs are unique, and generated sequentially across the entire user space. My next stop was Google. I wanted to see if Google had kindly indexed this particular photo. [As it turns out, this particular photo was indexed by Google, so the jig was effectively up at this point but sometimes, Google might not be that helpful].
Assume the answer is no. Google has not indexed the photograph. The next thing to do then, would be to invoke the following magic URL.
http://flickr.com/photo.gne?id=<photo id>
Alternately, you could use the photos.getInfo API call at this point. Voila. The URL above frames the photograph in a Flickr informational page; which… among other things gives the user ID of the person who uploaded the photograph. Once you know the user ID, finding the details of that person is a matter of the right API call again: in this case people.getInfo. Done.
As it turns out, the genius embedding the photographs in [his/her/it's] “anonymous” blog had hosted the photograph in a Flickr account which uses [his/her/it's] real name. Permit me to conclude with the following photograph.
Anonymous. In the words of Inigo Montoya, “You keep using that word. I don’t think you know what it means”. So, in short - even if you can’t make sense of the jumbled letters and numbers in the Flickr URL, they may give a wannabe stalker some valuable clues as to your identity. Don’t display photographs from a Flickr account which uses your real name and expect to remain “anonymous”. It ain’t gonna work.
On 21-Oct-06 at 3:14 pm,
rastiadu karaya wrote:
hmm, so drac, who were you trying to stalk?
Out with it! :p
On 21-Oct-06 at 5:54 pm,
Darwin wrote:
I think the only way someone could trace me (if they really really wanted to) would be to read my hi5 rants and figure out who I am on hi5. After all, I have not come across many people with a ‘both middle fingers up’ display picture to ward off the unsavoury types.
That said, considering what a small world Sri Lankans are, chances are that ‘annonymous’ bloggers would have common friends who know each others real identity, thus allowing them to figure out who he/she really is.
On 22-Oct-06 at 1:15 pm,
savi3 wrote:
interesting… i guess those anonymous bloggers with Flickr/hi5 accounts must be shivering in their shoes..hehe..
so what’s ur real name? i don’t know where to look so i thought i’d ask and see what the response would be
On 23-Oct-06 at 1:50 am,
N wrote:
I gave up on the whole anonymous thing awhile ago, bloody pointless….as an aside, I did come across Darwins hi5 account very randomly….hehe…I didnt know people could be tracked of their flickr accounts though, very impressive drac..
On 23-Oct-06 at 11:36 am,
drac wrote:
Rastiadu Karaya: Surprisingly (and probably unconvincingly
), I wasn’t specifically trying to stalk anyone; I just noticed that an “anonymous” blogger had embedded flickr photos. I knew that person’s name anyway, but as a thought exercise - I wanted to see if I could work my way backwards to the Flickr account, as it were.
Besides, the Flickr account shouldn’t actually give any more information than a blog account, just that … as I said … this genius decided to use [his/her] real name for the account.
Darwin: And now you’ve told all of us how to find out who you are
I think the common friends thing actually is quite common - unless you deliberately not out yourself as a Sri Lankan and keep personal details out of the blog equation.
N: Complete anonymity is one thing. Someone googling your name to find your “real” webpage (my webpage does have occasional legitimate uses
and coming across this blog would be … uh… embarassing. Used to happen at an earlier place.
Savi3: Now that would be telling wouldn’t it?
[hint: you may know me by my real first name from several years ago on another blog. See if you can work it out from there 
]
On 25-Oct-06 at 6:05 am,
N wrote:
Ok not that I’m a stalker or anything but it took me about 5 minutes to figure out you real name…just used some info off this blog, google and voila! Man this internet thing aint as anonymous as I thought:)…and I’m about 95% sure I’m right;)…
On 25-Oct-06 at 9:35 am,
drac wrote:
omg you stalker you!
heh, I’m sure you got it right… the only thing I need is for people to search for my real name and not get this blog as a prominent (first page) hit - now if that did happen, I’d worry more.
On 26-Oct-06 at 5:33 pm,
Sin wrote:
I’d like to point out for the record that I don’t Flickr. How’m I don’t on the anonymous front?
On 22-Nov-06 at 10:22 pm,
Darwin wrote:
Erm just a quick question, what if the photo you ‘trace’ ends up telling you that you do not have permission to view the photo?
On 23-Nov-06 at 11:04 am,
drac wrote:
Darwin: That’s an interesting case
got an example? [Usually, that should still give you enough information to track down the username but maybe Flickr does it differently now]
On 24-Nov-06 at 7:11 pm,
Darwin wrote:
Darn it! Ok try tracing this, dont laugh by the way.
[link removed]
On 24-Nov-06 at 7:39 pm,
drac wrote:
You could have just done this via email, you know
Tell me if you want the link removed.
On investigation it seems that they’ve [Flickr] closed the hole (because it was a hole) in the recent updates
Excellent. Back to the drawing board for now. I’ll ponder possibilities.
I didn’t laugh. Really. I just went “coooooool!” because I can’t really think of a much better use
I think their GuestPass feature[1] is for just this eventuality.
[1]: http://www.flickr.com/forums/ideas/12716/
On 25-Nov-06 at 1:01 am,
Darwin wrote:
Ok you can remove the link and could you pleaaaaase email me the solution please? (in English because me and computer stuff simply do not mesh well).
Thank you! And I’m not a stalker, honest.