prostoalex writes "The MSN Messenger ban of outside clients and cited security issues might be explained by yet another Microsoft move. The company's Internet unit, MSN, contacted third-party providers like Trillian and Odigo with a suggestion to buy access licenses. From the ZDNet article: 'Running an (IM) network is expensive,' said Lisa Gurry, group product manager for MSN at Microsoft. 'We can't sustain multiple other people's businesses, particularly if they charge for certain versions of their software. We're introducing licensing processes for third parties like Trillian.'"