If you are ever concerned about private messaging, BitMessage offers an easy solution. Bitmessage is a P2P communications protocol used to send encrypted messages to another person or to many subscribers. It is decentralized and trustless, meaning that you need-not inherently trust any entities like root certificate authorities. It uses strong authentication which means that the sender of a message cannot be spoofed, and it aims to hide "non-content" data, like the sender and receiver of messages, from passive eavesdroppers like those running warrantless wiretapping programs. If Bitmessage is completely new to you, you may wish to start by reading the whitepaper:
Windows, Mac and Source Code available here:
A community-based forum for questions, feedback, and discussion is also available on the subreddit:
To install BitMessage on Ubuntu (and other linux distros) go to your terminal and type:
git clone git://github.com/Bitmessage/PyBitmessage.git
Once its finished, run this...
BitMessage should now be installed with a link your menu or dash or by running that last line in your terminal window again.
* You may need to install git and python for the codes to work.
Give it a try and good luck!