1. A computer-implemented method: receiving, by a system that includes an automated speech recognizer, data from a client device; determining that at least a portion of the received data is likely sensitive data, wherein sensitive data is data that is deleted by the system without being stored in a log of data that is received from client devices, or that is deleted within a predetermined period of time of receipt by the system; before the at least a portion of the received data is deleted, providing the at least a portion of the received data to a model training engine that trains recognition models for the automated speech recognizer; and after the at least a portion of the received data is provided, deleting the at least a portion of the received data.