Google, Intel, IBM, Apple and IAC are all under the Justice Department's microscope as investigators try to determine whether tech companies have agreed not to poach each other's employees, this making it harder for professionals at the firms to change jobs. If they have made some kind of pact, they may be breaking antitrust laws.

The key term here is "may be."

Such agreements are "very close to the line," said Melissa Maxman, an antitrust lawyer at the law firm Cozen O'Connor. "They're not agreeing on price, but they're kind of agreeing on costs." Skilled computer scientists with some management responsibilities, for instance, often make base salaries of $180,000 to $210,000. Compensation for the most sought-after workers typically soars far above that and includes bundles of stock options and bonuses.

The Wall Street Journal, which broke the story last week, says the DOJ won't confirm the investigation. But several companies told the Journal they've gotten requests for information on their hiring practices. Some said there are agreements, but they only stop each other from cold calling another firm's employees.

-- Mark Feffer