LizaAlert, a Russian volunteer organization that provides search-and-rescue operations for those reported missing, worked with MegaFon, the mobile phone operator, to improve missing person operations. Using an in-house algorithm applied to its dataset of mobile phone data, the telecommunications company provides LizaAlert with a list of people who might have been in the vicinity of the missing person before their disappearance. These individuals then receive a SMS/MMS message, inviting them to share