On: Mobilewalla used cellphone data to estimate the demographics of protesters

[andai]

How was this data collected? They bought it, but how was it collected in the first place? Random apps with shady privacy policies?

[lxm → andai]

There's a whole cottage industry of apps monetizing user location in bulk.

They mainly position themselves as local deals apps (find the best restaurant, get a coupon from nearby store) and fitness apps (rewards for walking, running, etc.)

Both use cases call for always-on location sharing.

[Sindrome → andai]

Once I was approached by an ad company that wanted to use geo data gathered by Candy Crush that they purchased to target people with ads on their daily commute.