You can report black workshops polishing iPhone casings.

1. Trademark infringement can be complained to the Trademark Management Office of the Municipal Industry and Commerce Bureau or the Trademark Advertising Contract Management Section of the Industry and Commerce Branch, or you can file a lawsuit in the People's Court.

2. When requesting handling from the industrial and commercial administrative authorities, a written request must be made. The request shall state the cause of the request, the legal basis for the request, the name and address of the requester, the name of the infringer and the place where the infringement occurred, etc. Foreigners or foreign enterprises must entrust a trademark agency with foreign-related agency rights to handle the matter.