* Adioso vs. Bing: http://blog.adioso.com/sorry-bing-adioso-is-still-the-worlds...
* Posterous vs. Tumblr (and others): http://blog.posterous.com/hey-tumblr-users-got-comments-want...
Setting aside whether or not you want to be perceived as cutthroat or just straight-up douchey, the real question is whether or not this the most effective spin.
I think it might be better just to talk about how great privacy is at DuckDuckGo, perhaps in comparison to other search engines in general.
DDG calling out Google individually, Adioso calling out Bing individually, or in the case of Posterous, calling out other startups, isn't how I would play the game.