I think that explains: Intellectual property and software licence.
The client software of Ubuntu One is released for free public use under several open source licenses, primarily the GPLv3 and Creative Commons licences. See the licence text included with the code for details. Canonical grants you a non-exclusive, personal licence to use the server software while you receive the services from Canonical. You acknowledge that all intellectual property in the server software provided as part of the services belongs to Canonical or its licensors. You will not acquire any rights to the software or the intellectual property from your use of the services, other than as set out in this agreement and in the software licensing of the distributed client code.
https://one.ubuntu.com/terms/
