In some browsers you can disable iframes and then set them to be used on per site preferences. I know opera provides this functionality.

From [Quirksmode][1]:


> Disabling iframes
> 
>  - IE9: Internet Options -> Security -> Custom level (for Internet zone) -> (scroll down) -> Launching programs and files in an IFRAME ->
> set to Disable.
>  - Firefox: Go to about:config -> search for “frames” -> click on browser.frames.enabled
>  - Opera: Ctrl+F12 -> Advanced -> Content -> Style Options -> uncheck Enable inline frames

In addition, you could create a rule in a proxy, like [privoxy][2], to filter out all iframes and then to exclude the sites you want to have iframes. I believe the built in behavior only does iframe-adds, but could be adjusted. This will give you a more global blocking. You should really just need a regex to find the opening tag and to remove till its closed, might be some cases where it will break the page.



-------
Edit, it appears that opera does not actually disable iframes. I disabled iframes on the quirksmode link above, and it still registered the iframe. This is confirmed in the [Opera Forums][3]. I was hoping may the full quirksmode page was outdated.


![opera screenshot][4]


Probably best result to block at the proxy level before relying upon user scripts, browser features, etc. Also, more universal.

  [1]: http://www.quirksmode.org/iframetest.html
  [2]: http://sourceforge.net/tracker/?func=detail&atid=211118&aid=2635307&group_id=11118
  [3]: http://my.opera.com/community/forums/topic.dml?id=1505752
  [4]: https://i.sstatic.net/85mDm.png