A set of identifying elements of a first network is determined from a set of data. For each identifying element of the set of identifying elements, a first frequency at which the identifying element is associated with a first set of systems connected to the first network is determined, and a second frequency at which the identifying element is associated with a second set of systems of other networks accessible via the Internet is determined. It is determined if each identifying element is associated with the first set of systems at a greater frequency than with the second set of systems based, at least in part, on the first frequency and the second frequency. If an identifying element is associated with the first set of systems at a greater frequency than with the second set of systems, the identifying element is indicated as a fingerprint of the first network.