The following parable-like story is told about LMI by Steven Levy and used for the first time in "" (1984). Levy's account of hackers is in large part based on the values of the hackers at MIT Artificial Intelligence Laboratory. Among these hackers was Richard Stallman, whom Levy at the time called the last true hacker. When Noftsker started Symbolics, while he was able to pay salaries, he didn't actually have a building or any equipment for the programmers to work on. He bargained with Patrick Winston that, in exchange for allowing Symbolics' staff to keep working out of MIT, Symbolics would let MIT use internally and freely all the software Symbolics developed. Unfortunately this openness would later lead to accusations of intellectual property theft. In the late 1970s and early 1980s, to prevent software from being used on their competitors' computers, most manufacturers stopped distributing source code and began using copyright and restrictive software licenses to limit or prohibit copying and redistribution. Such proprietary software had existed before, but this shift in the legal characteristics of software can be regarded as a consequence triggered by the U.S. Copyright Act of 1976, as stated by MIT fellow Brewster Kahle. While both companies delivered proprietary software, Richard Stallman believed that LMI, unlike Symbolics, had tried to avoid hurting the lab. Stallman had proclaimed that "the prospect of charging money for software was a crime against humanity." He clarified, years later, that it is blocking the user's freedom that he believes is a "crime", not the act of charging for a copy of the software. Symbolics had recruited most of the remaining MIT hackers including notable hacker Bill Gosper, who then left the AI Lab. Symbolics forced Greenblatt to also resign at the AI lab, by citing MIT policies. So for two years at the MIT AI Lab, from 1982 to the end of 1983, Stallman singlehandedly duplicated the efforts of the Symbolics programmers, in order to prevent them from gaining a monopoly on the lab's computers. Although LMI was able to benefit from Stallman's freely available code, he was the last of the "hackers" at the lab. Later programmers would have to sign non-disclosure agreements not to share source code or technical information with other software developers. Lisp Machines, Inc. sold its first LISP machines, designed at MIT, as the LMI-CADR. After a series of internal battles, Symbolics began selling the CADR from the MIT Lab as the LM-2.