i just emailed tfl, asking for footage under freedom of information act,
You need to be asking for it under the Data Protection Act, not the FOIA - Have a google for "Subject Access Request CCTV".
You can use the FOIA to ask them for the location of all the cameras that they control and operate, and what the film / footage rotation time is.
You can use the FOIA to ask them for the location of all the cameras that they control and operate, and what the film / footage rotation time is.