One big challenge was that there was often, in these cases, confidential information that was justifying a listing, even sometimes presently.
I did two things. One was that because I had worked for the Canadian government for many years, Canada very nicely gave me high-level security clearance, which was then going to give me access to some information already under some of the sharing arrangements that the security clearance would carry. It also gave me credibility for certain states, which was very important. Then what I was able to work out with individual states was to just build up the trust: you share the information with me, and I share it with no one—not my staff, not the committee, not the individual. I can then take it into account in assessing the sufficiency of the listing.
That's what I did, and I managed to get a number of agreements.