A management expert is warning corporations to gird themselves for a potentially costly wave of lawsuits from employees claiming they are addicted to “crackberries.”

A professor at Rutgers’s School of Business, Gayle Porter, predicts in a soon-to-be-published study that disgruntled workers who feel they are unable to turn off their personal digital assistants and mobile telephones will begin suing their employers for their technology addictions — and that such lawsuits could potentially cost corporate America hundreds of millions of dollars.

“If companies develop a culture in which people are expected to be available 24 hours a day, then they should be prepared for the physical and psychological consequences,” Mrs. Porter said. “Addicts exhibit extreme behavior and have no control over themselves. So a corporation handing someone a BlackBerry on his first day of work could be seen as enabling, even accelerating, a serious addiction to technology.”

Labor Day weekend traditionally marks the end of summer vacation for millions of Americans. These days, though, many executives on vacation carry small arsenals of mobile telephones and computers, even on the beach. From their sandy towels they keep close tabs on both the workplace and the capital markets. Friends and relatives, Mrs.Porter said, are now complaining that no one in these jobs is getting any rest or relaxation.

Those like Mrs. Porter who study business management issues say “workaholism” can be a potent and seductive psychological addiction. The condition manifests itself in an employee who can’t delegate work, share responsibilities, or function as part of a team, preferring to take on every task himself. He becomes unable to separate himself from the workplace at the end of the business day — to the point where thinking about his job takes precedence over his personal relationships and hobbies.

When the worker’s life unravels around him, he looks for someone else to blame. “He can’t sue his BlackBerry, so he sues the company that he thinks caused his dependency on it,” Mrs. Porter said.

What the BlackBerry and other devices have done is to feed the workaholic’s need to be in touch with his colleagues on a constant basis, no matter where he might be, according to Mrs. Porter. Companies that foster corporate cultures in which it’s acceptable to send messages at any time of day or night are in danger of getting sued by workaholics who snap under the pressure of being available all the time, she said.

“It starts of innocently enough,” Mrs. Porter said. “A manager has an idea during a Saturday afternoon at home. Instead of jotting it down, he instantly texts some colleagues and tells them to check up on it. The manager does this because he doesn’t want to forget the idea, but his co-workers assume by the time-stamp on the message that he wants a response that can’t wait until Monday morning.”

To a certain extent, the courts are already dealing with cases involving “crackberry” addiction. A Dallas attorney, John Browning, said the trial of a Salomon Smith Barney trader who struck a motorcyclist is similar to what courts will be facing increasingly in the future.

As part of his defense, the motorist claimed he was distracted because he was making sales calls; Salomon Smith Barney officials countered that the broker wasn’t acting in the scope of his job while driving a car and talking on a cell phone.

Other Salomon brokers testified at the trial that the firm encouraged them to make sales calls whenever and wherever they could. “These crackberry addictions can come back and bite companies in the rear end,” Mr. Browning said.

Five states, including New York, have placed various cell phone restrictions on motorists. Some states now make the question of cell phone usage a required part of any official car accident investigation. Plus, plaintiffs and defendants can subpoena cell phone and BlackBerry records in order to prove whether a communication at the time of an accident was work-related.

Mr. Browning said he is seeing rampant BlackBerry use becoming an issue beyond auto accidents: He is beginning to represent employers and workers in cases where such devices are a part of stress-related claims. “There is a lot of truth to the crackberry term. I know a lot of people who can’t sustain a conversation because they’re always checking that gadget,” he said

Mrs. Porter said companies will be more successful in dealing with technology addiction lawsuits if they begin telling employees that it’s okay to turn off their BlackBerries for a couple hours a day. Companies that say Black-Berry use is strictly a matter of personal choice could be setting themselves up for legal trouble down the line.

In Japan, widows have successfully utilized the concept of “karoshi,” or death by overwork, to sue their deceased husbands’ former employers. In America, Mrs. Porter said, grieving widows of crackberry addicts will soon begin doing the same. “It’s just a matter of time,” she said.