Through chatting and reading threads I get the impression that many folks think that pedophiles are all smart, extremely tech savvy, operating in networks that share information and collaborate to fool law enforcement. There may be some of that, but there are also plenty of Joe Schmoes who download or trade CSAM material without being especially clever about it. I remember when I was a teenager downloading porn I found more than a few probably-illegal photos just by accident*. If you want to find such images you can, it doesn't take an organized "network".
* edit - this was 25 years ago, admittedly, and much of what I downloaded came from randos on AOL. Things might be different now.