WHAT IS CTRL+U? It’s a shortcut that allows you to see the source code of any webpage. So, if you don’t wanna anyone viewing or stealing your HTML codes, first you have to disable the right mouse click in your blog and then read this tutorial to learn how to block CTRL+U.
First, go to Customize > Edit HTML. Using CTRL+F, find your <body> tag and then replace it with THIS code. Click Update Preview and then Save. Go to your blog, try to use CTRL+U and, if nothing happens, is because the code is working properly.
Like this post if you agree! ;)