Controlling use of a telephone line includes receiving a specification from a first entity that defines one or more supervisory controls on use of a controlled telephone line by a second entity. The supervisory controls specify people with whom the second entity may or may not communicate over the controlled telephone line, and times at which the second entity may or may not communicate over the controlled telephone line. An indication of desired communications between the second entity and a third entity at a particular time over the controlled telephone line is received. A determination is made as to whether the desired communications are consistent with the specified supervisory controls. The desired communications are controlled when the desired communications are not consistent with the specified supervisory controls. In addition, the supervisory controls enable the first entity to interrupt existing calls over the controlled telephone line.