1. A method comprising: receiving first motion data corresponding to a first object including a geography through which the first object is traveling; receive an entropy of the geography; receiving second motion data corresponding to a second object; determining whether the second object is following the first object based on the first motion data and the second motion data and the entropy of the geography; receiving additional information from a source different from the first object and the second object; determining whether the second object poses a risk to the first object based on the additional information; and in response to determining that the second object is following the first object and that the second object poses a risk to the first object: providing a notification to a subscribing party, the notification indicating that the second object is following the first object and poses a risk to the first object.