It's corporate America, not government, that is emerging as the clearest embodiment of Big Brother — the all-seeing, all-knowing entity in Orwell's novel "1984."

With technology already available or on its way, corporations can block your e-mail from particular senders, stop you from printing documents deemed too sensitive and record instant-messaging conversations among workers.

"People worry a lot about the FBI spying on them," said Lewis Maltby, president of the National Workrights Institute. "But your chances of being spied on by the FBI are one in a million. Your chances of being spied on by your boss are better than 50-50."

Spying? Hardly, according to Microsoft Corp., America Online Inc. and others developing the technology. Rather, they say, they are merely helping companies exercise their right to monitor use of their computers and networks.

Companies need more control to improve computer security and block junk e-mail, and such industries as financial services and health care face federal requirements to record communications, advocates of the technology say.

With most of these products slated to be released later this year, it's unclear how and how many companies will use the technology.

But in recent years, companies including The New York Times, The Dow Chemical Co., Xerox Corp. and others have fired employees for Internet use deemed inappropriate.

Companies can now spy on workers by intercepting e-mail messages or even installing software to secretly record keystrokes.

As new technologies get rolled out, critics brace for more legal battles. With few — and outdated — laws in place, they say, employers' ability to monitor instant messages and Internet-based phone calls is creeping uncomfortably close to policing basic conversation.

"There's just a train wreck that's coming," said Ted Schadler, an analyst with technology research firm Forrester Research.

There's a balance somewhere between privacy and regulatory compliance, and "it's going to take a few painful lawsuits," he said.

Microsoft, AOL and Yahoo! are developing corporate versions of their popular instant-messaging services. All let companies archive instant messages that employees send. In some cases, a company can decide who may message whom — and even block rank-and-file employees from reaching the chief executive. Such a technology could create hurdles for whistle-blowers.

A 1986 federal law restricts employers from deliberately listening to personal telephone calls at work. Some states have passed laws requiring employers to notify employees that their e-mail may be monitored. But there's little else, critics say.

That means it's up to employers to decide how far is too far.

"It's a completely legitimate concern," said David Weld, chief executive of MessageGate, a message-filtering company.

But so are corporate fears of hacker attacks and government demands for recording communications, he said.