Sam Price

Sam Price was an employee of Miss Kizlet whose Facebook was found by Clara Oswald using face-match. She used this information to discover where Kizlet's offices were.

On the orders of the Great Intelligence, Miss Kizlet reset her and all other employees to factory settings, and they returned to their true selves. (TV: The Bells of Saint John)

Behind the scenes
The Facebook profile was based on the episode's production assistant Samantha Price. (DWMSE 37)