The Department of the Army v. Blue Fox, Inc., 1998 case involved a dispute over whether a contractor (Blue Fox) could obtain an equitable lien on funds held by the government (Department of the Army). The issue arose when a prime contractor hired by the Department failed to pay Blue Fox for its subcontracted work. Blue Fox sought relief under the Administrative Procedure Act and argued that it was entitled to an equitable lien against funds still owed by the government to the prime contractor. However, in this case, Supreme Court ruled against Blue Fox stating that sovereign immunity prevented them from imposing such liens on public property or money unless Congress explicitly waived this immunity. The court found no such waiver in either federal common law or statute applicable here - particularly not within Miller Act which protects payment rights of subcontractors in federal construction projects but does not grant explicit consent for suits seeking recovery directly from U.S Government.

In the dissenting opinion for the Department of the Army v. Blue Fox, Inc., Justice Stevens argued that a contractor should be able to obtain an equitable lien on funds held by a government agency if those funds were intended to pay for work performed by that contractor. He disagreed with the majority's interpretation of sovereign immunity and believed it was not applicable in this case because Blue Fox was not seeking damages from public treasury but rather specific relief tied directly to its unpaid labor and materials. Furthermore, he pointed out that allowing such liens would provide necessary protection for subcontractors who otherwise have limited means of securing payment when prime contractors default on their obligations. The denial of such remedy, according to him, could lead to unjust enrichment at taxpayer’s expense as government agencies might end up benefiting from goods or services they did not fully pay for.