The media, including BBT (link below) and the BBC, are reporting that LHR has been fined £120,000 by the ICO after an employee lost a USB drive, which was subsequently found by a member of the public.
The ICO confirmed that among the files on the stick were details of up to 50 HAL aviation security personnel, but would not comment on reports that it also contained "national security details such as a timetable of patrols that was used to guard the airport against terror attacks and the exact route the Queen took when using the airport".
Heathrow said that, following the breach, changes had been made including a company-wide information security training programme.
Heathrow fined for lost USB stick data breach