U.S. Patent and Trade Office U.S. Patent and Trade Office

A hammock-canoe drawing, U.S. Patent No. 299,951, is displayed in a June 1884 publication of the U.S. Patent and Trademark Office in Alexandria, Va. Critics of the patent system say it's too easy for people to save a slew of semi-realistic ideas, then sue when a firm separately tries to make something similar. Bloomberg via Getty Images hide caption

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Bloomberg via Getty Images