MSNBC host Krystal Ball was in close communication with leaders of an online boycott aimed at advertisers on Rush Limbaugh’s popular radio show, e-mails between the boycott leaders indicate.

Attempting to discover the identity of an infiltrator in their group, the #StopRush leader @Shoq (aka “Shoq Value,” who is believed to be an activist named Matt Edelstein) indicated that Ball had warned another member about the suspected “right wing disrupter.” The other member had “already inquired with Krystal last week, and Krystal said ‘we don’t like or trust this guy,’” Shoq wrote in an e-mail published Thursday by Brooks Bayne at The Trenches.