Children will do as their parents have been doing in front of them. Their observation of what you do is what needs to concern you the most. It is the responsibility of the parents to teach their kids proper values and the way to act responsibly. In today’s world, it is inevitable that technology, and especially the internet will have to be discussed and properly handled. We tend to get so much from the internet. There has never been this much collection of information in one place. But to use it well, one has to be responsible about it. Since they shall at some point access the internet, it is beneficial for all concerned if you can teach your kids how to interact with the resource responsibly. Here are some of the things you can do.
You need to tell them the meaning of bad behavior online, and what good behavior is. The demonstration of what is right from wrong can apply in this scenario. You need to tell them not to ever engage in cyberbullying. They need to know the importance of not hurting others online. They would also not like being the ones getting hurt that way. They need to see the value in being kind to others. When they see a positive way of navigating the internet, any negative and malicious influences shall not stick.
You need to put in place parental controls and find a kid-friendly search engine. This is how you will know more about the kind of sites they visit. It shall also block any attempts to visit something not suitable for them. They need to know of the good sites they can visit and what info they can freely share. By putting too much info out there, they put themselves in grave danger.
You then need to teach the older kids some of the laws that touch on online behavior. They will now see what consequences await those who harass others online. This is also how they come to appreciate the gravity of haring nude photos with friends online. They will be seen as violating child pornography laws, which gets them branded as sex offenders. They may have been having some fun. Under the influence of peer pressure, or facing blackmail, whatever the case, their lives will never be the same again. They need to report any such attempts to you.
You then need to lead by example. Kids tend to emulate more of what you do, and less of what you say. They will, therefore, do what they see you do with your devices and online presence. You should at all times give a good example.