I need to figure out the best way to determine if someone is the actual owner of a website. I don't just mean the domain although in a lot of cases that might be the case.
My first inclination was to have them put a special comment in their HTML that my program can scrape. e.g.:
<!-- @webcode:1234 -->
One possible problem with that approach is someone in theory could add it in the comments on their page or some other way to add content. Although I'm not sure anything I have them do couldn't be gotten that way.
My other idea was since I was planning on also offering a JavaScript widget was to just scrape that although I didn't want to necessarily force them to add the widget.
<script type="text/javascript" src="http://yoursite.com/widget/widget/A4923D2342JF"></script>
What other mechanisms could be employed to determine ownership/control of a website?