Your cell phone, IM, and social networks are all a digital extension of who you are. When someone you're with pressures you or disrespects you in those places, that's not cool.
I overheard a great conversation yesterday. Two girls were chatting behind me in the queue in the Post Office. From their discussion about school options and examinations, I'd say they were around 14 and 15 years old. Here's part of the conversation, it really made me smile.
Girl #1: My mum doesn't even know I'm on Facebook.
Girl #2: Oh gosh, you're on Facebook too? So am I. My parents don't know either; my mum doesn't like the idea of me being on it.
Great free booklet to help parents and teachers with teaching digital citizenship. Presents a good balance between safety and benefits of social networking.