Is there a way to prevent my web images from appearing on someone's cache folder? (1 Viewer)

[David Baranyi]

Through HTML encryption, I was able to prevent most methods of image theft on my web site, but there is one problem: the cache folder. This folder not contains web pages but also the images associated with them. Any sophisticated image thief knows how to find the cache folder on his computer and take any image from my web site. This disturbs me.

Is there a way to prevent images from appearing on someone's cache folder?

 

[Scott L]

It's real easy to grab images off sites. You can Print Screen just about anything pixel for pixel.

 

[JamesHl]

I don't think so. For the person to see the image it has to be sent to their computer, and they control how things are cached on their system. The only way to prevent this would be to not show the images at all, I think.

If you find a way to do it I would be interested in knowing what it is.

 

[Lary Larson]

I'm not sure this is what you need, but I think you can prevent a page from being cached using a META tag. Check here.

 

[David Baranyi]

Larry, the META tag is for pages only. I already use a scheme (not a META tag) to prevent page caching.

 

[DaveF]

and take any image from my web site. This disturbs me

As said, if they can be viewed on screen they can be copied and/or printed. You can make it harder for people, but you can't really prevent it.

You can take steps, such as digital watermarking, to help show proof of copyright, if you find them used without your permission.

But if you're this concerned about image theft, perhaps you shouldn't put them on public display.

 

[Cees Alons]

David,

Your web server sends the image to their computer. It has to be inside the computer and on the graphic card to be seen on their screen. How would you prevent anyone to keep it a bit longer?
BTW, html-pages can always be copied too. You cannot prevent that.

Even, they don't have to use a well-known browser.


Cees

 

[Todd Hochard]

If I can see it on my screen, I can grab it. There's nothing you can do about that, AFAIK.
But, ditto this-

But if you're this concerned about image theft, perhaps you shouldn't put them on public display.

What's the big deal?

Todd

 

[Michael_Gamrat]

If they know the filename, couldn't they just make and http request to your server from a command prompt? Then, the file would go into any directory that they wanted, instead of just the cache dir.

 

[MarkHastings]

You can make it harder for people, but you can't really prevent it.

True. A lot of places will program a photo gallery into a flash file so that you can't download the images. This doesn't prevent the user from grabbing a screen capture, but it does help the casual stealer. It also helps prevent people from badnwidth stealing where they use your web site URL and post photos into forums (like this one).

Face it, protecting images on the web is like protecting CD's from being ripped. There's always a way around it, your only defense is to make it harder because the average person will give up more easily than others or not have the proper means (or knowledge) to edit a screen grab. Or do what Dave suggests and don't put them on the server at all.

 

[Vince Maskeeper]

Did you guys go this his site? It disabled screen caps via windows, and 2 screen cap apps I had also failed.

http://www.megamii.com

And there is no way to find the file names because all the links are hidden in buttons, source code is diusabled, and so are all the file and edit menus.

In order to get in, I had to save off the opening page, find the link to the second index (http://www.megamii.com/index2.html) and from there- new window navigation had the proper toolbars (in Mozilla atleast), which allowed for saving the files and looking at the code.

Once I got to a poster page, I couldn't right click but I could save and get the html code... I got into the page source for the files but the img scr tags end up invalid if entered directly... But if you save the page in mozilla, it just saves all the content- so I got the files no problem- all done within maybe 1 minute...

Most of the files were broken into two parts- and a and b element... and so you'd have to put them together into one...

One thing that would help you would setup every page under index2 to open the next page with no toolbar, forcing someone who bypassed the opening (like I did) to look up the links in each step in order to get a browser with proper toolbars to save you images.

The only way to protect content is not to publish it.

-Vince

 

[MarkHastings]

It disabled screen caps via windows, and 2 screen cap apps I had also failed

I hit the "Print Screen" button and then pasted it into Photoshop with no problems.

 

[Vince Maskeeper]

Odd, didn't work for me. I tried all the poster pages, hitting print screen (or alt-printscreen) didn't copy it to the clipboard. Weird.

 

[MarkHastings]

Odd, didn't work for me.

Ahh, you must be using Explorer. It didn't work for me in Explorer, but it did work in Netscape 7.1. The funny thing was I had Explorer opened to that web page and I couldn't get it to work in Netscape, but once I closed Explorer, it did work in Netscape.

Now I'm starting to think. Can it be considered an illegal thing to disable the print screen button? I would think that any sort of disabling of keys on your keyboard should be wrong.

 

[Vince Maskeeper]

Seems legally comparable to prior restraint... usuallythe law sides with freedom and punishment for offenses over restrictions in the name of preventing them- at least in cases of speech.

 

[JamesHl]

Illegal like against the law? As long as it doesn't affect the functioning of the button otherwise, which I don't see how it could.

 

[Dave F]

When that site disables screenshots, it is disabling functionality even outside of that window. I minimized it, and was still unable to use the print screen function for other windows. I couldn't use print screen until I actually closed that window.

It looks more like a security exploit than a security function, IMO.

-Dave

 

[Brian W. Ralston]

Check this page out.

Go to www.flytecomm.com

on the left click the orange button to track a flight.
The easiest way is to pick an arrival and departure airport (say LA and NY)

In the list of flights for the day....click on one that is in flight currently. When you print the page.....the picture of the map with the plane on it will not print. It will print the page....just where the map should go it puts another gif image there saying Authorization error.

When you right click on the picture of the map with the plane in flight....it will save another .gif file to your disk (Not the one with the map)......one that says you are not authorized to view the picture. There is a law that forbids them from providing a way for you to print out the pictures of plane in flight and their relative position in the air.....and my print screen function seems to be disabled as well.

Hmmmmmmmmmmmmmmmmm???????????

 

[MarkHastings]

When that site disables screenshots, it is disabling functionality even outside of that window. I minimized it, and was still unable to use the print screen function for other windows. I couldn't use print screen until I actually closed that window.

Yeah, that's what made me reply with the 'illegal' comment. Maybe illegal wasn't the best word (I like Dave's term "security exploit" better), but I think there should be a big deal made of that because it did screw with the function of the system.

At least, the site should make you accept an agreement stating that you understand that the "Print Screen" button will be disabled. This may not seem like a big deal, but without making a big deal, it could lead to worse things.