Effectiveness vs Complexity
As current security consists in building walls around enterprises, systems, and applications, getting around these security walls (e.g. firewalls), to share information and knowledge, can introduce significant operational complexity, apart from often increasing security risks and limiting the content and value of shared information.  The operational complexity typically results in delays, inefficiencies, redundancies, and technical problems that hinder collaboration and frustrate collaborators.  Together, the increased complexity, costs, risks, and content value limitations can significantly constrain the productivity that collaboration is meant to provide.