Two,terms that are different.
Trademark
Copyright
Harley Davidson get to enforce Trademark
FBI gets to investigate Copyright.
Part true, part not true.
Copyright applies to the workproduct of a creative effort - that could be text (eg, a book, magazine article, a speech, or an depiction such as a drawing, paining or photograph, etc). Trademark is a symbol or logo that uniquely identifies a product. The most famous trademark examples are the Coca Cola logo and the GE monogram.
Ownership of either gives the owner the right to restrict or prevent use by others, and it is normally left to the owner to initiate actions.
Police agencies don't enforce copyrights, but occasionally do get involved in trademark issues. In the past, the former US Customs Service would occasionally do spot checks on merchandise purchased outside the US by travelers and would confiscate items bearing counterfeit trademarks. While I suspect that they still have the authority to do that, they have other priorities today and I don't recall being asked to show merchandise for customs inspection when returning to the US in at least 30 years.
I believe that the modern Immigration and Customs Enforcement agency may still occasionally check shipments of commercial merchandise for fraudulent trademarks although that is probably not their primary focus. And there have been instances where the Consumer Products Safety Commission has gotten involved in situations in which fraudulently-labeled products created consumer safety issues - the most famous being the instance in which bolts with counterfeit strength markings found their way to several automotive manufacturers.