Posted by John Hosking on 05/27/07 10:25

chancegardinner@yahoo.com wrote:
>
> Til recently this URL: http://www.oceancitycam.com/images/board1.jpg
> went to a webcam of a boardwalk in Maryland. The jpeg changed about
> every 5 seconds.
>
> Now when you go to that URL you get a a message:
> "Visit Beach-net.com Web Cams."
>
> However if you go to the page where the webcam image is embedded it
> appears as usual: http://www.oceancitycam.com/
>
> Checking the current URL for the pic,it appears to be the same as it
> has been: http://www.oceancitycam.com/images/board1.jpg
>
> Somehow, they have made the pic accessible only within the wepage.
> Does anyone know how they do that?

The site checks for the referrer. When I turn off referrers in my
Firefox, I only ever see the ersatz image
http://www.oceancitycam.com/images/hotlink.jpeg, even within their main
page. I must have referrers enabled, and I must be accessing the
board1.jpg image via their site. They're doubtless enforcing this with
..htaccess files.

See, for example, http://en.wikipedia.org/wiki/Hotlink and
http://altlab.com/htaccess_tutorial.html.

--
John

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