Microsoft will introduce new terms of service in October which have privacy and legal implications. Previously Microsoft wrote in their terms that it would only use your content as long as it was necessary to provide a service to you. This has now been updated so that Microsoft can use your content to 'provide, protect and improve' all Microsoft products and services. This means that e.g. Microsoft could make any document you created with a Microsoft product searchable with Bing. Microsoft at least hints to more integration as it says that its "cloud services" are being designed to "be highly integrated across many Microsoft products".
The change also means that personal information which previously only could be used to provide a single service now becomes available to Microsoft in its whole. Your data could be used for something totally different than you thought it would be used for when you signed up. Where Microsoft before didn't combine data, the company is now able to build profiles about people where it knows you're a Xbox gamer, to who you send e-mail with Hotmail, what kind of documents you write on Office.com and what kind of files you store on your Skydrive.
Another change is that Microsoft requires you to to resolve disputes with them through arbitration. With this change in its terms it joins companies like Paypal and Netflix which have similar clauses in their terms and basically it means that you give up your right to take Microsoft to court with all benefits such a judge which will hear your case and the right to appeal, which rights do not exist in arbitration proceedings. Besides that, you're also no longer allowed to bring a class action suit.
The updated agreement will take effect on October 19, 2012 and will become automatically in effect if you continue to use Microsoft services after that date.
