Online predator conversation gone wrong

Tried to have 'the talk' about online safety with my 10yo and it did NOT go how I planned. I was trying to explain that sometimes people online aren't who they say they are and he immediately got defensive like I was accusing HIM of something? Then he said 'you don't trust me' which wasn't the point at all. How do you bring this up without making them feel paranoid or like you're accusing them? I want him to be safe but also not terrified of the internet.