An anonymous reader writes "In what seems to be a recurring theme with Facebook as the social networking giant adds features, competing apps that use Facebook integration risk being cut off due to the terms of service surrounding the API. For example, 'Voxer CEO Tom Katis told AllThingsD that the company got an email on Thursday saying that Facebook wanted to hold a phone call to discuss possible violations of a section of the company’s terms of service. The section in question centers around the use of Facebook’s social graph by competing social networks.' Similarly, 'Within hours of Twitter launching its Vine video-sharing application on Thursday, Facebook has cut off access to Vine’s "find people" feature, which used to let Vine users find their Facebook friends using the Vine application.' You have to ask yourself: is it really worth developing an app that integrates with, or worse runs completely on Facebook's platform?"