Social media and emerging mobile technologies have sparked radical shifts in human behavior, with people worldwide spending an average of 2 hours and 15 minutes daily on social networks. Facebook, Instagram, and Twitter have more than 2 billion users globally. Social networking site use has risen dramatically by all age groups, with the highest use among 18-29 year olds (see Figure below). Every second, Twitter users send 6,000 tweets, amounting to 500 million tweets per day. Instagram users post approximately 95 million photos, generating 4.2 billion likes, each day. A newer platform, Snapchat, has 178 million daily users, 60% of whom are under 25 years of age. They share an average of 3 billion snaps, or rapidly vanishing photos, every day. Researchers at Penn are turning these Tweets, posts, and snaps into innovative data sources that hold vital clues about behaviors, emotions, preferences, opinions, and social networks—all with potential implications for population health. Through the analysis of keywords, images, phrases, emoticons, likes, and hashtags, Penn teams are turning troves of digital information into human-centered health interventions and educational initiatives.