Answer: Yes, they can seize the equipment and arrest the owners.
Step-by-step explanation:
Under the plain view doctrine, the law enforcement officers may seize illegal contraband even without a warrant when it's observed in an officer's plain view. The officer must legally be allowed to be there, and the officer must have probable cause to believe that the seized objects relate to criminal activity.
In this scenario, while looking around the house,if they found various pirated movies and DVD duplication equipment, they can seize the equipment and arrest the owners. Piracy is theft. The officers found t pirated movies and DVD duplication equipment. Downloading a film or copying a movie without paying is a breach of copyright.