Mark of the Web
No, not me! But more a feature of Internet Explorer that enhances security when running web pages from a particular source. This is a protective feature that will run a web page in the security zone it was saved from (as long as it is more restrictive than than Local Machine zone).
Anyone that has been playing with "WPF/E" and launching simple samples they have created using Internet Explorer may have seen the following dialog:
This is because of the WPF/E content sitting inside the HTML mark-up. To make it easier to debug and test then you may want to add the following comment to the top of your HTML:
<!-- saved from url=(0023)https://www.website.com/ -->
This will get rid of that dialog and allow you to test as if it were running live on the web.
More information on Mark of the Web to stop WPF/E pages showing the IE security warning dialog