Are you worried about the possibility that kids can chat with the wrong people on the internet? You are concerned about all your reasons, with all the predators, deceivers, hackers, and other cyber criminals.
Yeah, of course you talked to the kids about not talking to aliens, but every kid's kid seems to make his parents more experienced. And many simply do not understand the dangers; the Internet is so harmless to them. And that's why stinging predators for children and young adults. On the Internet it is very easy for predators to prepare for their children's friend; they may even pretend to be the child's age.
But what can you do with it? In the beginning you can do what every day thousands of people do daily by using reverse email searches to check email addresses for those who email children. Easy to use; you only find a web page that reverses the search for emails and enter your email address in the search box. This site attempts to specify the owners of the address.
But there is a catch. There are hundreds of billions of email addresses, and most sites provide limited access to them. In particular, free websites can find addresses in a given service provider database or in a particular directory.
So, instead of spending hours on dozens of free websites, hoping that someone can do what you need, you can try one of the premium sites that are more likely to help you. Their cost is usually nominal.