The author goes over some aspects of using the internet and educating the public about what could be or is illegal to perform. Then goes onto offer some simple and effective ideas for cyber-hygiene. I would say the most serious actions listed are recording VoIP without consent, faking an online identity, collecting information on those under 13 years of age, bullying and trolling, and finally using torrent services. The first four I listed are very serious because they involve an active intent from the user to perform harmful or potentially harmful activities.  These things range from theft, identity theft, and harassment. The last one using torrented services is the most serious copyright violation because again I believe that the user would have an active belief of bypassing proper channels. The other are copyright infringements but are generally in the realm of what could be simply the easiest way to enjoy a particular media.