prevent from linking css from others sites

Question

I have a comerce css on my site. I use IIS and vendor says that others can use my css fonts because they know the url. Is it possible to set server or something so that only my site can use it ? It is about cufon

Answer 1

Things you can do:

1. Give up. If your users can see it, they can steal it. Similarly, don't expect to protect your site from users viewing its source code.
2. If the font is a vector font, rasterize the font for all the font sizes you support, but no others. This may have a negative impact on browsing experience of your users. This makes stealing your font give less useful data, but doesn't actually stop the theft.
3. Replace all use of the font with bitmaps. Much more work to steal in that case, and only gives the user rasterized version of font (and not necessarily all the letters). You can create a special text UserControl that sticks a bitmap where-ever you put it, so this isn't actually that much work to do or maintain. It does increase the bandwidth requirements for your page, though. It also forces you to do some of the layout by hand that is normally handled by the browser, which could add heavy maintenance costs or minimal maintenance costs, depending on how your site's layout works. And as with #2, it can have a negative impact on browsing experience of your users. It also hurts accessibility, though not absurdly so since your UserControl will presumably use alt text to duplicate the text.

I strongly recommend #1.