NEW YORK - Another battle line is being drawn in cyberspace.
     A Phoenix law firm that has angered thousands of computer users for broadly advertising on the Internet has devised a blunt response:  It now plans a new service to enable other businesses to do much the same thing.
   The firm, Canter and Siegel, last month plastered more than 6,000 electronic bulletin boards with a message offering its legal services to help immigrants participate in the federal government's "green card lottery," a program which awards people permits to live and work in the U.S.  That brought in $50,000 of business — and a deluge of harshly critical reaction aimed at the lawyers, Laurence A. Canter and his partner and wife, Martha S. Siegel.  They received 36,000 e-mail messages in two days — some of them even seeking legal services, the lawyers say. Beyond that, thousands of public postings labeled them "scum," "jerks," and "Sueman & Shyster," among other epithets.
    Undaunted, Canter & Siegel not proposes /Cybersell, as service to aid other business brave enough to endure the wrath of Internet users.  They already have their first client, a maker of super-oxygenated water that claims health benefits.  They are setting up a pricing scheme that is surprisingly inexpensive by other ad standards: $500 to get access to the 6,000 "news groups" or bulletin boards frequented by millions.
    That price also allows for a handsome profit for the law firm.  It costs only $30 typically for someone to get access and send out a message to all the news groups on the Internet.  So why pay Canter & Siegel's hefty fees?
     "Buying access is one thing, and knowing what to do with access in another thing entirely," says Ms. Siegel.  "We have the marketing and technical expertise to make this happen."  Mr. Canter says that the law firm especially hopes to appeal to advertising agencies.
      Canter & Siegel's approach is heresy by the standards of "netiquette" that govern behavior on the quasi-public Internet.  The bulletin boards are devoted to individual topics, ranging from the latest plot twists on "Melrose Place" to cellular biology.  the law firm's ad was widely viewed as off-topic junk mail.  Internet users don't object to ads posted in specified ad areas, but they do abhor widely disseminated messages posted blindly to unrelated bulletin boards.
    Many Internet veterans feel the Canter & Siegel posture exploits the fact that no one governs the network.  "People like Canter & Siegel are taking grotesque advantage of liberating technology that supports the free and open exchange of ideas," says Robert Raisch, president of Internet Col, which helps businesses use the Internet.
    The outrage raises questions of whether a business might do more harm than good by advertising through the law firm.  But Mr. Canter sees a bit of hypocrisy in this cyber-flap.  He says many users, while complaining that the firm violated acceptable-use policies on the Internet, have violated those policies themselves by issuing defamatory and obscene statements.
    Mr. Raisch of Internet Co. had hoped to quell such disputes by recently proposing, as any Internet user can, a new system of new groups set aside for ads allowing users to access them at their will.  But Canter & Siegel calls that approach "a black hole" because those ad-oriented bulletin boards would be "set apart like a pariah," says Ms. Siegel.
    She adds: "Our fate has been that we're making a lot of money.  If a bunch of hysterics want to scream and yell and make fools of themselves, then I don't feel that they warrant respect."