Because librarians are reporting a trend of snooping into reading habits -- from the Moral Majority investigating who takes out sex education materials to husbands checking on their wives' tastes in fiction -- a growing number of state legislatures are moving to make sure that public library records are not an open book. In New York, where the Assembly has just passed a library privacy bill, librarians surveyed have reported numerous attempts to get reading records -- not only by husbands watching their wives but also by employers checking on their workers. In Oregon, the Moral Majority tried to learn the names of people who had checked out a sex education film it found objectionable, and that's the kind of thing that sponsors of various bills say they want to guard against. "We believe that this information is nobody's business," said New York Assemblyman Steven Sanders, adding that he wanted to send a "strong message" about his state's attitude toward library snooping. Henry Reichman of the American Library Association in Chicago said seven other states have passed laws guarding library records from prying eyes. The seven are California, Virginia, Maryland, Iowa, Minnesota, Florida and Nevada. In addition to New York, Oregon has a bill under consideration. The New York proposal would allow law enforcement authorities to seize library records only after getting a court order. Reichman said that during the 1970s, many prosecutors went on "fishing expeditions" looking for reading materials of suspected radicals. Federal authorities recently obtained the Colorado library checkout records of John W. Hinckley Jr., the man accused of shooting President Reagan.