Can Software track my moves when I walk from one CCTV camera to another?

The idea of CCTV sounds promising enough to think about it deeper. I imagine, that if I walk down the streets of London, being continuously filmed, I can be tracked down from somebody human behind the camera when I leave the angle of the one camera, walking into the next.

Yet I believe that if a computer could do this task, it would be a lot more efficient (efficiency is never bad, only goals can be bad).

Does anyone know, if this software exists? And what resolution would one need?