Twentieth Century Fox allowed the copyright on some old documentary footage to expire. Another company took the footage, deleted an hour, added 30 minutes, and sold it as their own…with no attribution.
This is perfectly legal under copyright law. If the copyright has expired, anyone can use the material, and they do not have to even attribute it to the author. It’s nice to do so. But legally, it’s not required.
So 20th Century Fox decided to sue under trademark law. The Supreme Court has laughed at them. (OK, they ruled 8-0 against them. Same thing.)