Digital citizens: The first thing has to be student safety. We also can't assume that they are all learning this from their parents. In an age when some kids accept any friend on facebook (people they don't know or aren't even friends of friends), they need to be taught how to use this technology in a manner that is safe for them. The second and third things are about sources. I want to make sure that since students will do research online, they know how to do it well. They need to know to check multiple sources to corroborate their findings (and how to do this). In addition, they need to know to check to see if a source is reputable (and how to).
I went to the ed tech website to look for some other resources. I came across another website where the kids can make comic strips. This one looks more promising - students can design their own backgrounds; this would be necessary for the succession activity.
I think when students are first learning the concept of digital citizenship we, as teachers, need to require it in our projects. For example, checking multiple sources and verifying those sources can be a part of the project. We can also use this opportunity to talk about safety. Once we have built this foundation, hopefully the kids will see the benefits of it and internalize those habits.
I would address the idea of digital citizenship with parents in two ways. First of all, it can be addressed on my website. Secondly, I can discuss it at back to school night and tell the parents how they can support this at home.