To discuss the formation of an attorney client relationship, I give my students a hypo in which a lawyer gives a presentation at a seminar open to the public and then stays for a reception during which the lawyer answers questions about legal matters from one of the attendees. Months later, the lawyer gets a motion to disqualify in a case because the person the lawyer had talked to during the reception argues the lawyer had been his lawyer in the past.
I don't remember where I got the hypo originally, but now I know how one jurisdiction has decided to avoid the problem it points to. As reported in Legal Ethics in Motion, on August 7, 2015, the Ohio Board of Professional Conduct issued Formal Opinion No. 2015-2, in which it concludes that lawyers may present a legal seminar to prospective clients, after which lawyers may provide law firm brochures and information, but cannot answer attendees’ legal questions or personally hand out promotional brochures. The law firm brochures and information must be left near the exit of the seminar, so that the lawyer, or a third party on the lawyer’s behalf, does not personally distribute the materials to attendees. Legal Ethics in Motion has more information here.
I understand the spirit of the Opinion's conclusion and agree it might be a good idea for attorneys' to be extra careful when handling questions from the audience after a seminar, but I am not sure the opinion's suggestion (if it were to be considered an actual rule) would survive an attack under the first amendment case law. The opinion's suggestion is a ban on an attorney's right to talk to people who come to the attorney for guidance. I am not sure how strong the argument of the state would be that the circumstances implicate the "Ohralik dangers" (the few state interests that have been held to support an argument for state regulation of commercial speech. On the other hand, if the regulation is seen as imposing merely a delay, or waiting period, then it may be argued that the state can impose it under the reasoning of Florida Bar v. Went for it.... but since most agree Went for it was wrongly decided... I am skeptical.