That last bit makes it quite easy to discover that a DMCA notice was faked, thus quite risky for the sender: either they provide contact information for themselves that will be repudiated by the actual copyright holder should anyone question it, or they provide contact information for the actual copyright holder and are unable to carry the charade beyond the initial message and the takedown will not last beyond the initial ~2 weeks for a counterclaim to take effect (plus they'd catch the notice of the actual corporate legal department, who are unlikely to appreciate the impersonation).