GoToMeeting / GoToWebinar incessant firewall warnings

Please talk with developers at, each time I launch a webinar, I get incessant Firewall warnings (launching new programs, linking to other programs, changing registry. Maybe 50 warnings, over several minutes. Then when the webinar ends, I get more warnings about accessing programs.

Or, is this software I should Block? Seems like good software, so I allow it.