A computer-implemented method for data loss prevention may include (1) identifying a network configured with a data loss prevention system, (2) identifying a file subject to a data loss prevention assessment within the network, (3) identifying a source of the file, the source of the file causing an entry of the file onto the network, (4) determining, based on the source of the file, that the file is subject to a data loss prevention policy, and (5) applying the data loss prevention policy to the file based on the determination that the file is subject to the data loss prevention policy. Various other methods, systems, and computer-readable media are also disclosed.