Is there even a way to make sure your 100% private while using technology?
Kind of, if you are connected to the web the answer is no though.
IN a faraday cage, no web connection one could do stuff with out the world knowing. This is how one should create bitcoin wallets... and then destroy the computer on which your passphrase was written.
If you wanted to send a message you could get a sha-256 encryption program, run it on an offline computer, burn the message to a CD and then send the message on your online PC. Other person would need to decrypt on an offline comp or your passphrase is compromised.
Easiest way to think about it: if you are connect to the web the gov and hackers are watching everything you type/create and copying it to their servers.