Twitter receives information about its users from both members and non-members, and therefore needs to ensure that the Privacy Policy provisions for the collection and use of such personal information in a responsible and lawful manner. Note the implications of jurisdictions with regards to this policy.
The enforceability of these Terms is on the basis of a contract agreement between the parties on the rights and duties created by the contract and that the agreement will be legally binding upon them. Twitter users are, therefore, contractually bound across ALL incorporated policies. Users are bound by agreement to all such documents.