AFAIK the copyright scan only happens on files shared from certain types of Drive accounts, the assumption presumably being that while Google doesn't know or care if you have rights to possess data, they can be reasonably sure you wouldn't be using Drive links as the means of distributing many well-known files (video, music, software, mostly) if you had rights to do so.
How far Artificial Stupidity runs into the weeds from that basically sound beginning appears to be "still farther."
FYI Drive also does scans (configurable on business accounts) for data such as likely accidental PII disclosures on shared data, and anti-malware checks on at least Windows and Mac executables, installers, and dmgs.