Not that this is going to help. The NSA is probably tapping the fiber at the ISP's backbone in front of Google. Why do you think it is called PRISM? It's probably named for the way they are splitting the fiber and recording everything.
In the case of DDG, that would be difficult. DDG uses SSL. If you make a mistake and type "duckduckgo.com" instead of " https://duckduckgo.com" , it will automatically redirect you to the secure page. Unfortunately, that redirect gives a man-in-the-middle and opportunity to hijack your connection, even with SSL; however, that's tricky enough that its hard to imagine anyone pulling it off without ever being noticed.
As long as the SSL cert isn't compromised, I don't see how this is possible.