Legal Question in Civil Litigation in California

They can not do so if it is merely a subpoena, but can if it is a search warrant issued to the police and permits the impounding of evidence as to a suspected crime.

In civil litigation, if you are not a party to the lawsuit, you could be served a subpoena. But that does not give the process server the right to come into your home and remove belongings. You would have to bring the computer for inspection to one of the subpoenaing parties or their attorney. But you would also be allowed to object, provided you did so timely upon receipt of the subpoena.

That's what a search warrant means, if it gives that specific authority. Not merely a subpoena. Hope you demanded to see the document.