Mr Bloomberg cited concerns over some proprietary business information that may be contained within his tax returns.

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These include the heightened risk of industrial espionage during inspections and the possible loss of proprietary business information through other means.

CENTERFORSECURITYPOLICY: Center for Security Policy | EXCERPTS OF TESTIMONY BY FRANK J. GAFFNEY, JR. before the SENATE ARMED SERVICES COMMITTEE

Indirect costs will likely include the loss of proprietary business information during intrusive inspections by international monitors and lost production time due to these inspections -- that may take as long as ten business days.

CENTERFORSECURITYPOLICY: Center For Security Policy

Business aviation is also a powerful productivity booster: When traveling aboard business aircraft, employees can meet, plan and discuss proprietary information in a secure environment and without fear of industrial espionage.

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Owners may be able to win over employees by explaining their logic, such as maintaining productivity and safeguarding proprietary information, says Rocki-Lee DeWitt, a professor of management at the School of Business Administration at the University of Vermont.

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