The paper analyses, in the context of electronic contracts, the supposed contractual nature of the authorization that users give for the use and treatment of their personal data. It is asserted that that authorization can only be considered as legally relevant when a contractual relation is present. However, in practice, not in every and any case a contract is concluded, since the conditions for a valid consent by the user can be absent in some. With this purpose, two recent decisions of the Chilean Supreme Court are especially examined.