I got the impression the NYT is waging this battle more to figure out who was behind fraudulent comments rather than to determine which comments were fraudulent and which were legitimate.

First rule of any good investigative reporting: follow the money. Whoever paid for the comments must have had some motivation for committing fraud and identity theft en masse.

The fact that the FCC is fighting to keep the comment-purchasers IP address(es) secret is telling in and of itself though I suppose.