Department of Commerce

Screen Warning Banners


Systems with external communications may need to alert potential users that inappropriate use may be subject to prosecution. Public Law 99-474 requires that a warning message be displayed, notifying unauthorized users that they have accessed a U.S. Government computer system and unauthorized use can be punished by fines or imprisonment. Although, the warning does not prevent unauthorized use of the system, it does facilitate prosecution of violators (i.e., failure to notify an unauthorized user that it is a Government system may make prosecution more difficult, regardless of how much damage is done to the system).

Some of the systems now in use are intended for unrestricted use by the general public (e.g., Internet-based systems used for widespread public information dissemination), a situation not prevalent when P.L. 99-474 was enacted. Thus, due to their adverse impact on the intended user population, highly restrictive warning banners may not be appropriate. The choice of which screen warning banner to implement is up to the system owner and should be based on system specific technology limitations, data sensitivity, or other unique system requirements. In this section describe the rationale for electing to use or not use warning banners and provide an example of the banners used. Where appropriate, state whether the warning banner was approved by the Department of Justice, Computer Crime Unit.

System opening banners/messages that include the word "Welcome" in the log-in sequence may be interpreted to authorize the use of the system by anyone. Such interpretations are not appropriate for systems restricted to access by pre-authorized Government users. If access to your system is limited to Government users (including contractors and other pre-authorized individuals) and your banner includes the word "Welcome" it should be removed to allow easier prosecution of unauthorized users.

Example Warning Banners
Selection Rationale

"You are accessing a U.S. Government information system, which includes: 1) this computer, 2) this computer network, 3) all Government-furnished computers connected to this network, and 4) all Government-furnished devices and storage media attached to this network or to a computer on this network. You understand and consent to the following: you may access this information system for authorized use only; unauthorized use of the system is prohibited and subject to criminal and civil penalties; you have no reasonable expectation of privacy regarding any communication or data transiting or stored on this information system at any time and/or any lawful Government purpose, the Government may monitor, intercept, audit, and search and seize any communication or data transiting or stored this information system; and any communications or data transiting or stored on this information system may be disclosed or used for any lawful Government purpose.

This information system may contain Controlled Unclassified Information (CUI) that is subject to safeguarding or dissemination controls in accordance with law, regulation, or Government-wide policy. Accessing and using this system indicates your understanding of this warning."

System is for Government use only and all transmissions may be monitored.