In a connected world the force of aligned purpose may be stronger than the boundaries of an organisation. The line drawn by management, supported by formal rules, becomes artificial and may even proof to be counter effective to what is meant do be achieved by that delineation.
This counts for internal boundaries where informal networks are more effective than the organisation chart. It also counts for external boundaries where customers resent the way an organisation shuts them off and come up with new ways to pursue their objectives. When companies hold on to obsolete business models, customers will circumvent them.