a study by harvard school of public health (hsph) released in the october 12, 2012 issues of the journal science discussed how phone data helped curb the spread of malaria in kenya. the researchers mapped phone calls and texts made by 14,816,521 kenyan mobile phone subscribers. when individuals left their primary living location the destination and length of journey was calculated. this data was then compared to a 2009 malaria prevalence map to estimate the disease's commonness in each location. combining all this information the researchers can estimate the probability of an individual carrying malaria and map the movement of the disease. this research, a result of data philanthropy, can be used to track the spread of similar diseases.