Question: I know there is no such thing as a dumb question but this is: Can you serve contextual based ads via adsense or others on a site that is entirely behind https?

Answer: 
**Update:**

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> We’ve updated the AdSense ad code so that it now supports secure ad serving through Secure Sockets Layer (SSL) on Hypertext Transfer Protocol Secure (HTTPS) web pages. This means that publishers with secure sites, i.e., sites that are served over the HTTPS protocol, can now use AdSense ad code to serve SSL-compliant ads. Examples of secure websites include many financial services sites, e-commerce sites, and social networking sites.
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[Google is aware of the issue but does not offer a properly configured HTTPS version of their code at this time](https://www.google.com/support/adsense/bin/answer.py?answer=10528). It'll work by swapping out http for https, but as mentioned above you'll get various errors in browsers.
You can but visitors will receive a message that your site contains secure and none secure data in internet explorer. Most other browsers have a way to communicate this state aswell.