Digital Citizenship is interesting not because it falls out of the realm of what a good citizen should be but because of the unexpected outcomes that seem to catch us by surprise. Those outcomes are most likely our biggest challenge. Luckily, some of them have been revealed by others thus we don't have to learn the hard way if we take our citizenship seriously. I first started with the list of three as requested but upon further examination I believe it is in the end our very ethics that is the umbrella for all. I mean being ethical is that you would never knowingly involve yourself in anything illegal or infringe on others' privacy or well being. Doesn't it also mean you have the responsibility to look at the validity of the information you are viewing and/or presenting to others. Plus, shouldn't we always operate erring on the side of caution thus being safe in our work, our postings, our presentations, our relationships, etc. One of the hardest things in life is to realize that even in our best efforts we can make mistakes but doing it willfully is unethical. So those good first and repeated teachings of being a good citizen to all are valid here. The hardest piece may be the staying abreast as to what is out there. Which, by the way, may be impossible so I believe it is back to ethical behavior in all things. Ugh, sometimes a tough one to teach. Providing the opportunity for open conversation (school, home, global) and creating ethical self-determining learning may indeed give us that needed venue.
FYI - There is a district Atomic Learning course on just this "Internet Safety Workshop". http://www.atomiclearning.com/k12/internet_safety