1. A method of extracting privacy policy information for a website from its text, the method comprising: by a processor, determining using statistical classification whether the text is relevant to the website privacy policy; when the text is determined to be relevant to the privacy policy, determining, by the processor, whether at least a portion of the text is relevant to a category within a taxonomy of categories related to the privacy policy; when at least a portion of the text is determined to be relevant to the category, extracting from the text, using a first classifier, privacy policy information associated with the category; by the processor, deriving data based on the extracted privacy policy information, the data being a subset of the privacy policy and providing a summary of the privacy policy that includes the website's policies regarding collection of personally-identifiable information, collection of non-personally-identifiable information, sharing of collected information, and permission to opt-out, wherein the summary of the privacy policy, when presented to a user, obviates the need for the user to read the entire text of the privacy policy such as portions of the privacy policy concerning matters other than the policies on the collection of personally-identifiable information, the collection of non-personally-identifiable information, the sharing of collected information, and the permission to opt-out; using the processor, presenting to the user when the user visits the website, the data along with a user prompt to accept or decline the privacy policy; and by the processor, restricting access to at least a portion of the website when an instruction is received, in response to the presented data, to decline the privacy policy.