Ever since the controversial 2006 launch of its now ubiquitous News Feed feature, Facebook has seen a cycle of surprise, anger and later acceptance from its users when it launches or changes a major feature. But Facebook's requirement that all business profile pages convert to the Timeline format by the end of this month means that companies, nonprofit groups and other organizations that use Facebook pages are having to explain those changes to their customers, and in some cases may face the brunt of user anger about them.