The troll shared secret information with Russian officials in a way that endangered intelligence sources.

More information.

Sharing secrets with Russia (or other countries) is not necessarily a bad thing. In some cases it is useful for diplomacy. However, endangering sources is a harmful practice; states do this at their peril.

One of the few criticisms of Wikileaks that I agree with is that sometimes it endangers intelligence sources (and other people) by failing to redact information.

Dubya was criticized for revealing the identity of Valerie Plame. He did this merely to score political points.