Thirteen states have passed laws that protect farmers and food producers from criticism that could cut back on their sales, and environmentalists and consumer advocates are warning that the laws are limiting the public’s right to know about potential dangers. Some publishers and broadcasters, fearing lawsuits under the laws, have declined to publicize information about pesticides, herbicides, bovine growth hormone, lead in calcium supplements, and biotechnology controversies. Many lawyers believe these “veggie-libel” laws will eventually be overturned as unconstitutional, but for now the laws are scaring many people from speaking out.