O2 'shared mobile numbers with websites' The numbers were included as plain text in the header information sent by the phone to the website. Such data would be easy for a website owner to collect and use for sending SMS messages or making marketing calls. In a statement, the company said: "We investigated, identified and fixed it this afternoon. We would like to apologise for the concern we have caused. The company added: "The only information websites had access to is your mobile number, which could not have been linked to any other identifying information we have about customers." O2 said it had informed Ofcom of the incident and was had been in contact with the Information Commissioner's Office.