HTTP question

[b***@hotmail.com]

If someone on a forum wants to post a picture in his/her post, and that picture is on, say, Flickr, then they post a <img src= blah blah flickr.com/blah blah/pic.jpg> in their post right? (well, they post different, but that's what the forum software changes it to....?)
But does Flickr KNOW that it's a post on Mr. Forum that's requesting that picture? I don't know for sure if this is what is called "leeching" or not (sounds more like MP3 stuff to me!), but - what's there in the HTTP protocol to tell Flickr that it's Mr. Forum that's requesting the pic? Is it the Referer header? WHY IS THIS NECESSARY? I DON'T _WANT_ FLICKR TO KNOW!


Thanks.

[Robert Wessel]

Post by b***@hotmail.com
If someone on a forum wants to post a picture in his/her post, and that picture is on, say, Flickr, then they post a <img src= blah blah flickr.com/blah blah/pic.jpg> in their post right? (well, they post different, but that's what the forum software changes it to....?)
But does Flickr KNOW that it's a post on Mr. Forum that's requesting that picture? I don't know for sure if this is what is called "leeching" or not (sounds more like MP3 stuff to me!), but - what's there in the HTTP protocol to tell Flickr that it's Mr. Forum that's requesting the pic? Is it the Referer header? WHY IS THIS NECESSARY? I DON'T _WANT_ FLICKR TO KNOW!

It does depend on what the forum software does to the link, but most
typically it just pastes it into the HTML it sends to the browser
being used to read the post, and then it's the browser that makes the
request for the image.

Unfortunately your browser may well include an "Origin" in the HTTP
request, which will tell the image server what the page was that this
was embedded in. This is often one of the things suppressed if you
your browsers "privacy" mode turned on, but that doesn't help with
other people viewing the post.

[Barry Margolin]

Post by b***@hotmail.com
If someone on a forum wants to post a picture in his/her post, and that
picture is on, say, Flickr, then they post a <img src= blah blah
flickr.com/blah blah/pic.jpg> in their post right? (well, they post
different, but that's what the forum software changes it to....?)
But does Flickr KNOW that it's a post on Mr. Forum that's requesting that
picture? I don't know for sure if this is what is called "leeching" or not
(sounds more like MP3 stuff to me!), but - what's there in the HTTP protocol
to tell Flickr that it's Mr. Forum that's requesting the pic? Is it the
Referer header? WHY IS THIS NECESSARY? I DON'T _WANT_ FLICKR TO KNOW!

Yes, it's the Referer header.

I don't think Private Browsing mode disables this in most browsers. But
there are extensions available for them that do.