If a blog is not advertising the issue is whether the lawyer is subject to other Rules of Professional Conduct, and if so, whether these rules are constitutional under the First Amendment.
If lawyer blogs are not advertising, then what are they? I believe blogs could be categorized under several different umbrellas, including:
1. Public forums
2. News sources
For the topic of this post alone, I will limit my discussion to public forums. There are three classifications of forums: (1) Traditional public forums, (2) Limited public forums (or designated public forums), and (3) Closed forums.
Where an area is classified as a traditional public forum, the state may restrict the conduct only where the regulation is narrowly tailored to achieve a compelling state interest. Int’l Society for Krisha Consciousness, Inc., v. Lee.  A designated public forum is one that the state has granted limited access, and which the state proscribes such conduct may occur.  This conduct is subject to the same limitations as a traditional public forum. Lastly, where the forum fits in neither the traditional public forum nor designated public forum framework, the state regulation must only pass rational basis. 
First, a traditional public forum is one that has a “principal purpose...the free exchange of ideas.”  Furthermore, a traditional public forum is one in which the government has the “power to preserve the property under its control for the use to which it is lawfully dedicated.”  A public forum is not created merely because members of the public are permitted freely to visit a place owned by the government; the decision to make a forum open to the public must be intentional.  In Krishna, holding that airport terminals are not traditional public fora, the court reasoned that airports have only recently achieved their current size and character. Furthermore, due to the short history of air transport, it is only recently that religious and political groups have used airport terminals for the distribution of literature and similar activities.
Justice O’Connor’s concurring opinion discusses how the definition of the public forum must be expanded to meet the expectations of the current age. She states:
In my view, our public forum doctrine must recognize [the] reality [that an airport is one of the few government owned spaces where may persons have extensive contact with other members of the public], and allow the creation of public forums that do not fit with the narrow tradition of streets, sidewalks, and parks. We have allowed flexibility in our doctrine to meet changing technologies in other areas of constitutional interpretation, and I believe we must do the same with the First Amendment. 
The issue remains, therefore, whether the internet is, in fact, a public forum. This issue has been addressed in several United States Supreme Court cases:
In Reno v. ACLU the court addressed the issue of whether two federal statutory provisions “protecting minors from indecencies on the internet” were constitutional under the freedom of speech clause of the First Amendment.  Holding that the statutes were unconstitutional on the basis of vaguess and overbreadth, the court stated:
Through the use of chatrooms, any person with a phone line can become a town crier with a voice that resonates farther than it could from any soapbox. Through the use of web pages, mail explorers, and newsgroups, the same individual can become a pamphleteer. . . The content on the internet is as diverse as human thought. 
However, the issue of whether the internet was indeed a public forum was never reached due the fact that the court found the statute to be vague and overbroad.
The United States Supreme Court addressed the issue of the internet as a public forum in U.S. v. American Library Ass’n, Inc.  In Library Ass’n, the court addressed the issue the usage of the internet in the public library. The court held that the internet is neither a traditional nor limited public forum. In reasoning that the public forum doctrine does not apply, the court stated:
[T]his resource, which did not exist until quite recently, has not “immemorially been held in trust for the use of the public and, time out of mind,…been used for the purposes of assembly, communication of thoughts between citizens, and discussing public questions.” 
The court also stated that, to qualify as a limited public forum, the government must make an affirmative choice to open up the property for use as a public forum.  The court reasoned that, in the case of the internet, the government did not create the internet in order to create a public forum for web publishers. Rather, the internet is offered as a service at the library in order to facilitate research, learning, and recreational activities.
Turning to the issue of blogging: it is clear that the United States Supreme Court has not yet been willing to extend the public forum doctrine to the internet. Is this right, though? Our latest jurisprudence regarding the internet occurred in 2003, 8 years ago. In 8 years, many changes have been made to the internet. While the internet was once a place where email could be exchanged, and chat rooms could be visited, it is now the very center upon which the world turns. On the internet, among other things, we can shop, connect with old friends and new, meet significant others, read the daily news, check the daily weather, and countless other tasks.
There is no way that our founding fathers could have anticipated the existence of the internet. In addition, even if the internet as a whole would not be considered by the Supreme Court to be a public forum, what about blogging specifically? Seeing that blogging could be considered to be akin to a news source, wouldn’t it be relevant that the founders intended newspapers to receive the highest protection? I would argue that blogs are traditional public forums. Under the O’Connor approach, the public forum doctrine must be expanded to facilitate the changing times of the technology world we currently live in.
Therefore, if we were to take the O’Connor approach to the public forum doctrine, for a regulation of a lawyer blog (or any blog, for that matter) to be held as constitutional under the First Amendment, the regulation must be narrowly tailored to achieve a compelling state interest.  This standard is stricter than the intermediate standard used in the commercial speech realm.
In a later blog I will discuss (1) the state’s interest in regulating lawyer speech, and (2) whether this interest is narrowly tailored under the Model Rules of Professional Conduct.
 505 U.S. 672, 679 (1992).
 Id. at 679.
 Id. at 679 (quoting Cornelius v. NAACP Legal Defense & Ed. Fund, Inc., 473 U.S. 788, 800 (1985)).
 Id. at 679-680 (quoting Greer v. Spock, 424 U.S. 828, 836 (1976)).
 Id. at 780 (citing Cornelius, 473 U.S. 788, 802(1985)).
 Id. at 698 (O’Connor, J., concurring).
 521 U.S. 844 (1997).
 Id. at 870.
 539 U.S. 194 (2003).
 Id. at 205 (quoting Krishna, 505 U.S. at 679).
 Id. at 206.
 Krishna, U.S. at 679.