The most awkward possible use of the word “only”? The dialog above is part of IE8, and it is intentionally confusing. The intent is to trick you into clicking “Yes” unless you carefully parse every word above.
By clicking No, you’re saying “No, I want to see everything on the page.” They’re trying to err on the side of security, but in doing so, they’re knowingly confusing the user. And that should never be considered the safer choice
Instead, why not two simple buttons:
[Show Me Everything] [Block Insecure Content]
(Prompted by Gruber’s link to this Smileycat bit about another confusing Yes/No dialog box.)