Confiscating something due to its potential
to become illegal doesn't make any sense whatsoever. That would be like raiding the shoe store since all those shoe laces could be made into machine guns
. Or impounding cars that were capable of speeding, arresting women because they could be converted into prostitutes, or raiding grocery stores and hardware stores for selling materials you could use to cook an illegal drug or make an explosive device, etc. I don't think this would hold up in court if the owner of the shipment pursued the issue.