In Consolidated Edison Co. v. Public Serv. Comm'n (1980) 447 U.S. 530, 532, 544 100 S. Ct. 2326, 2331, 2337. 65 L. Ed. 2d 319 (Con Ed), the United States Supreme Court considered the constitutionality of an order issued by the New York Public Service Commission prohibiting utilities from including in monthly bill envelopes inserts discussing controversial issues of public policy. ( Id. at p. 532 100 S. Ct. at pp. 2330-2331.) The New York Public Service Commission argued that the subject-matter regulation in that case was permissible because it was viewpoint-neutral and was justified by the special interests of a government in overseeing the use of its property. ( Id. at pp. 537-540 100 S. Ct. at pp. 2333-2334.) In rejecting these arguments, the high court held that "the First Amendment's hostility to content-based regulation extends not only to restrictions on particular viewpoints, but also to prohibition of public discussion of an entire topic." ( Id. at p. 537 100 S. Ct. at p. 2333.) It further held that the utilities' billing envelopes did not constitute government property, the protection of which could justify a refusal to allow partisan political advocacy. (Id. at p. 540 100 S. Ct. at pp. 2334-2335.) As with the remarkably similar regulation at issue in Con Ed, section 453, subdivision (d), attempts to restrict public utilities' discussion of entire topics and cannot be justified as a permissible subject-matter regulation. (See Con Ed, supra, at pp. 537-540 100 S. Ct. at pp. 2333-2335.)