I would let the kids know that they need to understand how ever they speak on the web should be the same way they would speak to their mothers, with respect. What is online does not really disappear and can be found. We have a student assembly where our counselors speak about cyberbullying. I like the teacher's Cool Cat blog about digital citizenship. It can be used in the class as well as BrainPop, but our parents can be educated by sending home information to them with the first day packets.