You can bet the “dossier” Kerry compiled was on the personal lives of the Swiftvets, which is what he did when he tried to get back at them in 2004. He’s a simpleton and a slime ball.
Well to be reasonable, I don't recall that he did any such thing in 2004 and there's nothing in the article to suggest that he's doing that now.
The direct quote was that they were putting together a "documented portfolio" about SBVT claims which the paper apparently decided to describe as a "dossier" on SBVT. A dossier is a collection of documents about a subject or person, and there's nothing here that says they're collecting documents about individuals. People should just be careful in reading things into this.