Sorry, I updated with a much longer explantion about Freenet. It's not that using Freenet is illegal per se. It's that Freenet is loaded with child porn, and worse. And that investigators have tweaked Freenet software that logs content moving through all peers that they connect to. And there are databases with hashes of illicit content. So they see that your node is handling illicit content, contact your ISP to get your identity, and then SWAT you. That's how that ex cop in Philadelphia, who's still sitting in jail, after "forgetting" his FDE passphrase, got busted.