Field-of-use limitations in patent licenses may raise antitrust issues when such arrangements are used to allocate markets or create cartels.
The US Supreme Court held such arrangements legitimate in General Talking Pictures Corp. v. Western Electric Co.[3] By way of example, such a license might authorize a licensee to manufacture patented engines only for incorporation into trucks (the "truck field"), or to manufacture such engines only for sale to farmers (the "field of distribution to farmers").
[5] Furthermore, when field-of-use licensing is used to create a horizontal cartel by which product markets are allocated among what would otherwise be competitive licensees, the General Talking Pictures doctrine does not shield the arrangement from the antitrust laws.
In Hartford-Empire Co. v. United States,[6] such a cartel based on patents was condemned as an antitrust violation.
It has been argued that field-of-use limitations are inconsistent with W3C standards and with the GNU General Public License.