title: How secure are socket variables in socket.io?
body: <p>For example, if we were to assign a username on a socket.on function.</p>
  
  <pre><code>io.sockets.on('connection', function (socket) {
      socket.on('login', function (data) {
          socket.username = data.username;
      });
  });
  </code></pre>
  
  <p>How secure is it leaving the username as a socket variable? Is it only server-side?</p>