We had a client insist that the SSH prompt be changed to include a half-page rambling about it being an "proprietary system" and "access prohibited for non-authorized users", something like that. Failing to include their specific wording, when we did their new staging setup, was a critical, must fix now bug.
Their argumentation was that it was a regulatory requirement and would allow for prosecution.
These types of messages largely stem from NIST 800-171 (and related standards). Specifically NIST 800-171 has the control "Display a system use notification message with privacy and security notices consistent with applicable CUI [controlled unclassified information] rules before granting access to the system." So it is very common when dealing with companies that are government contractors or subcontractors. 800-171 also sometimes gets used as a security framework even when not dealing with the government so these requirements sometimes end up outside those contexts as well.
Their argumentation was that it was a regulatory requirement and would allow for prosecution.