A detailed contact list of opponents has a thousand and one uses. Most of those uses are best served by keeping the exact details in the list private.
A limited reveal that "the list" exists could be more effective at getting attention then full disclosure of the contents.
What does get disclosed must be accurate. Lists accumulate incorrect data pretty quickly, and critical details are always changing. Everything must be periodically revised.
It strongly behooves anyone who is making a list to be checking it twice.