Image Anti-Leech

[John Smith]

Hi,

I've been trying to play around with a simple script to stop people stealing
images (and bandwidth) but without much success :

strFolder="imageshidden"

strServer = lcase(Request.ServerVariables("server_name"))
If strServer="www.joebloggs.com" Then
strPic = strFolder & Request.QueryString("pic")
Else
strPic = "img/youarestealing.gif"
End If
Response.Redirect strPic
Is there an online tutorial or script for this ?

Thanks

John

[Boris Nikolaevich]

I think it would make more sense to test for the referring page, rather than
the server name... in other words, if the request for the image came from a
page on your server, display the image; otherwise display the alternate
image. I think the name is HTTP_REFERER but my memory might be off.

A few notes about this, though: since your "real" image is available as
yourdomain.com/imageshidden/realimage.gif, it's still possible for someone
to download it. Your script is a slight deterrent, not a prevention.

I have had problems with some browsers not including the HTTP_REFERER header
when loading images (or scripts) for a page. For the site visitors who are
using these browsers--IE for Mac is one of them--the "you are stealing"
image would always be displayed, even when the visitor tried to load the
page correctly.

The best advice I have heard--and it's been posted many times, in many
different groups--is "don't post images that you absolutely don't want
anyone to download." That's the only sure-fire way to prevent leeching.
"John Smith" <jo**@nospam.spam> wrote in message
news:bj**********@hercules.btinternet.com...

Hi,

I've been trying to play around with a simple script to stop people stealing images (and bandwidth) but without much success :

strFolder="imageshidden"

strServer = lcase(Request.ServerVariables("server_name"))
If strServer="www.joebloggs.com" Then
strPic = strFolder & Request.QueryString("pic")
Else
strPic = "img/youarestealing.gif"
End If
Response.Redirect strPic
Is there an online tutorial or script for this ?

Thanks

John

[John Smith]

Boris,

Thanks for that, I'll have a go at using the REFERER and also disabling the
script if the USER_AGENT is a Mac.

Thanks

John

"Boris Nikolaevich" <bo***@nikolaevich.mailshell.com> wrote in message
news:uN**************@tk2msftngp13.phx.gbl...

I think it would make more sense to test for the referring page, rather than the server name... in other words, if the request for the image came from a page on your server, display the image; otherwise display the alternate
image. I think the name is HTTP_REFERER but my memory might be off.

A few notes about this, though: since your "real" image is available as
yourdomain.com/imageshidden/realimage.gif, it's still possible for someone
to download it. Your script is a slight deterrent, not a prevention.

I have had problems with some browsers not including the HTTP_REFERER header when loading images (or scripts) for a page. For the site visitors who are using these browsers--IE for Mac is one of them--the "you are stealing"
image would always be displayed, even when the visitor tried to load the
page correctly.

The best advice I have heard--and it's been posted many times, in many
different groups--is "don't post images that you absolutely don't want
anyone to download." That's the only sure-fire way to prevent leeching.
"John Smith" <jo**@nospam.spam> wrote in message
news:bj**********@hercules.btinternet.com...

Hi,

I've been trying to play around with a simple script to stop people

stealing

images (and bandwidth) but without much success :

strFolder="imageshidden"

strServer = lcase(Request.ServerVariables("server_name"))
If strServer="www.joebloggs.com" Then
strPic = strFolder & Request.QueryString("pic")
Else
strPic = "img/youarestealing.gif"
End If
Response.Redirect strPic
Is there an online tutorial or script for this ?

Thanks

John

[Alan]

I remember seeing an article on the different methods to try, but I can't
remember where - sorry. One solution involved setting the image source as
the background attribute of a TD tag, and then putting a transparent gif in
the TD so that it overlays the 'real' image. When a use r-clicks the image
they get the properties/source of the transparent gif. Never tried this, but
I imagine the first stumbling block will be browser compatibility. Have you
tried a Google search? I doubt there's any foolproof way.

Alan

"John Smith" <jo**@nospam.spam> wrote in message
news:bj**********@hercules.btinternet.com...

Hi,

I've been trying to play around with a simple script to stop people stealing images (and bandwidth) but without much success :

strFolder="imageshidden"

strServer = lcase(Request.ServerVariables("server_name"))
If strServer="www.joebloggs.com" Then
strPic = strFolder & Request.QueryString("pic")
Else
strPic = "img/youarestealing.gif"
End If
Response.Redirect strPic
Is there an online tutorial or script for this ?

Thanks

John

[William Tasso]

John Smith wrote:

...
I'll have a go at using the REFERER and also
disabling the script if the USER_AGENT is a Mac.

I'm afraid you will find it's not reliable. Some of your visitors will be
operating from behind routers/firewalls/proxies or using ISPs that do not
send the referrer. There are also users that deliberately set their
browsers to withold that info.

Watch your logs and change image directory names regularly is one tactic
I've seen suggested.

--
William Tasso - http://WilliamTasso.com