Anti-hotlinking watermark on an image - how will Google react?

[glitterball]

I found a script that allows me to add a watermark to a hotlinked image (such as the new Google Image search results). The script would present a watermarked image to Google instead of the non-watermarked image presented to actual users.

Any speculation as to how would Google react to this?

[edited by: tedster at 2:10 pm (utc) on Apr 24, 2013]
[edit reason] removed a link [/edit]

[HuskyPup]

Apart from the image SERPs being a total mess at the moment whereby a simple Blogger page with nothing on it apart from the image and nothing else, you should be ok.

I have a lot of watermarked images in the results both old and new ones added in the past few weeks plus I have noticed that many more images in my widget sector have gained watermarks recently.

Incidentally I don't allow hotlinking whatsoever and do not even allow Google to display my image under "View Original Image". If users want to see them they have to come to my sites.

[backdraft7]

Go for it Glitter - I watermark some of my photos, especially if I post the on social photo sites or even FB. You can also digitally watermark them, but I haven't tried that yet. I have one photo in particular that has been ripped of many times and I've filed DMCA's on anyone who doesn't include a photo credit. I fully warn people in the copyright notice on my site, but most of these hit & run artists don't even bother to check. I take content copyrights VERY seriously and respect all copyright owners.

One thing that really corks me with Google is their addition of the full DMCA report from Chilling Effects at the bottom of the serps. What do casual users care about DMCA reports? Plus, it makes me look like an a-hole for filing to protect my content against a thief. Sorry if I trotted off topic a little there. I digress.

[Kendo]

Hotlinking is usually by way of a direct link to the image resource stored on the server. So how can a "script" come into play unless you are using a "mod" to filter all requests?

If anyone uses software to spider your site and then retrieve say "images" only, they will get them so fast that they won't even touch the sides on the way out or any "scripts".

If they are scraping content then that may be different.

[glitterball]

The script (.htaccess) works like this:
We check the HTTP_REFERER to see if it originated on our site. If not, we present a watermarked image.

Having actually tried to implement this script, I can see that it's not going to work for us.
Google seem to have done everything in their power to stop webmasters from preventing hot-linking. Why use an iframe, if not to bypass anti-hotlinking scripts?

The only way seems to be to present Google with a modified url of the image, so that we can watermark that one. Since this could be interpreted as cloaking and get us banned, I'm not going to implement it.