If these sites are being seized with no followup legal proceeding, this is outrageous and should not be tolerated. However, if this is just step one in some sort of court case for piracy against an individual, fine. That makes it no different than getting arrested on the street, or having physical items confiscated with the later court case determining if you were right or wrong.
The larger issue may be, what the hell DHS and ICE are doing enforcing copyright laws.