Oh my, perhaps we are getting somewhere after all.
>>14860372I don't think we can help you with a full list but we can certainly suggest a few sites you could put on it. After 4chan I'd say 9chan, furaffinity and deviantart are the ones most harmful to your son. He has claimed to be a furry a couple of times before, meaning a person who likes these animal-human hybrids. If you catch him looking at any sites which feature such pictures you should block them as soon as possible because the furry community is notorious for being full of groomers. This applies to Pokemon as well, you may think it's just a children's franchise but there are many unsavoury individuals in the community.
You also need to be careful about discord, the chat app that he uses. A person who uses discord can join a number of servers, these are chat rooms you only know the names of before joining. For example a child can get lured into joining one supposedly about cartoons when in truth he would not be talking to other children there but to groomers.