The Adoption Network Law Center based in California, but it is not licensed to provide services in Illinois.
Attorney General Lisa Madigan says that their online advertising is targeting Illinois residents.
Her office sent a cease and desist letter to a dozen online adoption providers early this year.
She says the Adoption Network Law Center was the only one that refused to comply.
A lawyer for The Adoption Network Law Center was quoted as saying that because its online ads don't originate in Illinois, it is not bound by Illinois law.
The center also cited a 1975 court case that found a state can't restrict advertising for something that may not be legal there, but is legal elsewhere.