A method of providing information, the method comprising interrogating a memory tag; receiving content from the memory tag by wireless electromagnetic communication in response to the interrogation, the memory tag comprising a memory and a transponder to enable the wireless electromagnetic communication; storing the content; sending a release request to an authorizer; receiving a release confirmation from the authorizer in response to the release request; and releasing the stored content in response to receipt of the release confirmation. The memory tag may contain encrypted content. A plurality of said release requests may be sent, each release request having an associated cost. An aggregate cost can then be calculated in accordance with the sum of the associated costs.