Years ago, mothers used to place their hands on their children's foreheads to determine if they had a fever. Thermometers now can provide more precise measurements and, thus, more appropriate health care. Like the thermometer, can we use social media to do the same for mental illness? But what do we risk by opening our social channels to algorithmic observance? Dr. Munmun De Choudhury has spent years investigating what our social media can say about our mental health.