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3D printers have spread from scientific labs to industrial workshops to private homes. And prices of 3-D printers continue to drop. Designers demonstrate a large number of different machines at 3D print shows. There are models that can produce complex copies of human organs. There are less costly 3-D printers that make toys for children or parts for home electrical devices. One German automaker recently demonstrated how the structure of a car could be printed in one piece. And a Chinese manufacturer advertised a house created with a 3D printer. Almost anyone can print exact copies of many kinds of objects with the help of a computer. But they also might violate the law in doing so. Julie Samuels is a lawyer with the civil liberties group Electronic Frontier Foundation. She says people should be careful about what they create with 3-D printers. She says printing a design that is protected by copyright might be a violation of law. 3-D companies are concerned about restrictive copyright protection laws. They say restrictive copyright laws could violate the rights of citizens. They argue also that such laws might suppress technological invention. The lack of legislation on 3-D printing will not stop the technology from spreading. Experts in the field say they hope new laws will not punish people for printing 3-D objects for personal use.