UC Berkeley faculty may be asked to accept confidential, proprietary, or export controlled data or material as part of a research project subject to a Non-Disclosure Agreement (NDA) signed by both the discloser and the recipient. NDAs may include licensing agreements which limit or prohibit the disclosure or transfer of the licensed data or materials.
NDAs and similar confidentiality agreements are permissible ONLY to the extent that they meet the requirements of the University of California's policies on openness in research (see links: Restrictions on Rights to Publish or Disseminate Information Resulting from Work under Sponsored Projects, Unacceptable Controls Based on U.S. Citizenship Status, Acceptance of Funds Restricted to U.S. Citizens.) That is, the information must be entirely peripheral to the research program (sufficiently remote from the intellectually significant portions of the research) and the disclosure restriction must not affect the ability to publish the research results.
In addition, if you accept confidential or proprietary information subject to a Confidentiality or Non-Disclosure Agreement, and the disclosure restrictions affect your ability to publish research results, the research itself will lose its characterization as "fundamental research" for export control purposes. Should the research entail information or software identified on US export control lists, and you wish to have foreign nationals participate in the research, you may be required to obtain an export license.
Of course, if the confidential data pertains to such information as personal health, income, or other demographic data that does not have a strategic significance (and is thus not identified on US export control lists), then export control restrictions on foreign national participation would not apply.