His advocacy of new laws for the online world to preserve traditional balance between freedom and efficiency.
To convince people that laws and judges should actively protect individual rights from encroachments made possible by new technology.
It's a cliche that the Internet changes everything. But people like Harvard Law professor Larry Lessig remind us that, even on the Net, some things shouldn't change: things like individual rights, free speech, and privacy. Because government and business can use Web software to trample fundamental rights, Lessig argues that courts and legislatures must fight back, or risk squandering the liberating potential of the Web.
The 38-year-old constitutional lawyer's impact is already easy to see. Justice Sandra Day O'Connor cited Lessig when the Supreme Court overturned the Communications Decency Act, and Judge Thomas P. Jackson asked Lessig's advice on an antitrust ruling against Microsoft Corp. But his real influence may be as a teacher: His students and friends are omnipresent in the emerging field of cyberlaw.
Free marketeers pigeonhole Lessig as an innovation-strangling liberal. But the ex-Teenage Republican says critics don't get it: ''The libertarian tradition is about using the law to help people.'' Conservatism, it seems, depends on what you try to conserve.