Confidentiality of returns restricts publication and access; unauthorized disclosure and false returns attract criminal and monetary penalties. Section 142 mandates confidentiality for information furnished under section 141: identifiable individual return information may not be published without written consent nor used in proceedings, and access is restricted to those engaged in collection, compilation or computerization for the Act, except for prosecution purposes. The provision creates offences for failure to furnish required information or willfully furnishing false information with monetary penalties and for willful unauthorized disclosure by persons involved in data collection or compilation, punishable by imprisonment or fine, subject to prior government sanction for prosecution. Aggregated class-level publication is permitted in the public interest by competent authority.