"lastActiveTimes": {
"3443534": 1456065265,
"675631492": 1456066386,
"8657643": 1456062331,
"255277634": 1456052450,
"6423324": 1456065173,
"235323452": 1456065096,
"3265233223": 1456066381,
"2432885644": 1456064016,
"7464340313": 1456062500
}In the HTML source code of Messenger.com you can find an object containing userids associated with timestamps of last activity – as shown above. Given this it’s really easy to scrape and combine this data in order to get to know each user his/her sleeping pattern.
How you can use Facebook to track your friends’ sleeping habits →