I read a very similar article in the ABA journal within the last few years. The second article was pretty predictable. If you have visited any law firm web sites, nearly all have prominent disclaimers stating that they are not giving legal advice and that email is not a secure form of communication. I don't think there are any secure forms of communication. All types of phones can be tapped or their signals intercepted.
Letters can go to the wrong address.
Email is just another form of communication that is more efficient than anything we have seen before. I agree that using email to solicite clients must comply with ABA Rule 7.3. The warning on Internet searches is valid. Attorneys should stick to established and reputable sites when gathering legal information. Just because something is written does not make it true or accurate.