In one illustrative example, TV usage data associated with a residential set-top box (STB) are obtained and stored over a plurality of repeated (e.g. weekly) time periods. TV usage pattern data associated with the residential STB are derived based on the stored TV usage data. A suspected illegitimate use of the residential STB is identified based on identifying a match or correlation between the TV usage pattern data and one of a plurality of predetermined commercial TV usage patterns. Further, for each listing data of one or more published listings of business hours, types, and themes associated with one or more commercial establishments, a comparison or correlation is performed between the TV usage pattern data and the listing data. A commercial establishment associated with illegitimate use is identified based on identifying a match or correlation between the TV usage pattern data and the listing data associated with the commercial establishment.