It’s time to grow up.
Deniability, Forward Secrecy are things which can be discussed on the forum. In the Court it does not matter. 
Have you heard about Manning and Assange?
They used xmpp (jabber)+OTR, chat logs were used in the Court. This is a real life.
According to a Jabber chat log, Manning asked a person called Nathaniel Frank – alleged to be Assange – whether he was any good at cracking a password hash. Manning sent Assange a hexadecimal string that she had found on her computer network.
No later than January 2010, Manning repeatedly used an online chat service,
Jabber.ccc.de, to chat with ASSANGE, who used multiple monikers attributable to him. 2 - Criminal No. l:18-cr-111 (CMH)