You retain ownership to your stuff. You are also solely responsible for your conduct, the content of your files and folders, and your communications with others while using the Services. We sometimes need your permission to do what you ask us to do with your stuff (for example, hosting, making public, or sharing your files). By submitting your stuff to the Services, you grant us (and those we work with to provide the Services) worldwide, non-exclusive, royalty-free, sublicenseable rights to use, copy, distribute, prepare derivative works (such as translations or format conversions) of, perform, or publicly display that stuff to the extent reasonably necessary for the Service. This license is solely to enable us to technically administer, display, and operate the Services. You must ensure you have the rights you need to grant us that permission.
[Update 2 - 7/2] - An update based on your feedback:
One of the main reasons we updated our terms of service was to make them easier to read and understand. It seems we've mostly accomplished that, which we're thrilled about. Some of you have written us with very understandable concerns about the legal-sounding parts. In particular, our new TOS talks about the licenses we need to run Dropbox. We want to be 100% clear that you own what you put in your Dropbox. We don’t own your stuff. And the license you give us is really limited. It only allows us to provide the service to you. Nothing else. We think it’s really important that you understand the license. It’s about the permissions you give us to run the service, things like creating public links when you ask us to, allowing you to collaborate with colleagues in shared folders, generating web previews or thumbnails of your files, encrypting files, creating backups… the basic things that make Dropbox safe and easy to use. Services like Google Docs and others do the same thing when they get these permissions (see, for example, section 11.1 of Google's TOS). We wish we didn’t have to use legal terms at all, but copyright law is complicated and if we don’t get these permissions in writing, we might be putting ourselves in a tough spot down the road. Not to bore you with the details, but please take a look at the license term in the TOS. We think it’s fair and strikes the right balance: “This license is solely to enable us to technically administer, display, and operate the Services.” We want to thank everybody who wrote in, understanding your concerns helps us make Dropbox better.
Drew & Arash