Yes, but prior to that they used getdropbox.com, not dropbox.net (or something of that ilk). I do believe they were able to lawyer a squatter into releasing the dropbox.com domain after they were proven successful.
I guess Dropbox ended up taking legal action against dropbox.com when they started placing ads for Dropbox's competitors. As a result, the domain holder ended up handing the domain over (no mention of purchase in the article).
What are the legal grounds for "lawyering" him into releasing the domain?