• Never login into such pages, and never use the chats among VPN is sufficient enough. The feds first stage is to monitor interactions, if there is no interactions they cannot obtain lots of metadata to pinpoint individuals.
• If trust is no option use a seedbox because this way on paper someone else does the work, here it same like a external VPN depends on several factors, reputation, trustworthiness, etc.

These steps are simple enough and the feds, even if they monitor the network, which they do among attorneys to send letters to your ISP only see some IP pools that are not connected to you. They only could contact your seedbox or VPN provider to ask for data to hand over, but in most cases they are limited by laws.

Despite the wrong claims, IRC, DC++, Usenet are still alive.