Major brands like Skype and phone companies have already promised law enforcement and other agencies access to you conversations, but anyone who thinks privately encrypted chat and voice calls are 'safe' from eavesdroppers... Really ought to read this:
http://www.ieee-security.org/TC/SP2011/PAPERS/2011/paper001.pdf
http://www.ieee-security.org/TC/SP2011/PAPERS/2011/paper001.pdf
