You'd be surprised what a conversation with someone who knows someone can yield. I used to cold contact authors and sources on interesting papers, including CRS, and had a better than 50% response rate.

Same with farmers. Whenever I called to talk about alternative crops to corn, wheat, and soybeans, once they realized I wasn't trying to get them to buy anything from me, they were happy to tell me about everything they were dealing with. Granted, it may have mostly been the coffee kicking in at 4 or 5am, but they didn't hold back about every pain in their ass from city hall to the capitol.