In one aspect, a method includes receiving query fingerprint data representing content received by a content-presentation device. The method also includes comparing at least a first portion of the query fingerprint data with at least one first reference fingerprint data set, where each first reference fingerprint data set corresponds with a respective channel. The method also includes determining that the query fingerprint data does not match any of the at least one first reference fingerprint data sets. The method also includes responsive to the determining, comparing at least a second portion of the query fingerprint data with second reference fingerprint data representing a modifiable content-segment. The method also includes detecting a match between at least the second portion of the query fingerprint data and the second reference fingerprint data. The method also includes responsive to detecting the match, performing an action that facilitates the content-presentation device performing a content-modification operation.