The first ruling by the new regulator agreed with Telkom that overseas call-back services violated the monopoly.
She also said that a service like Star38 could violate various state fraud laws.
The caller identification system has come under increasing attack from civil liberties groups that say the service could violate a caller's right to privacy.
All five judges found that the services violate the law even when telephone companies allow some customers to block the release of their telephone numbers.
And the court ruled by 3-to-2 vote that the services violate privacy protections offered by the Pennsylvania Constitution.
They plan to appeal the commission's decision, arguing that the service violates the state's wiretapping law.
He said a number of enterprises that had employed draftees before they entered the service were violating the law by dismissing them.
Ms. Reiter says the service violates the tradition of free theater.
If a service violates any of the required constraints, it cannot be considered RESTful.
Some people, including representatives of the United States Government, say the service may violate Federal telecommunications laws.