The simplest method. Click "Add Friend." If you are nervous, personalize the message: "Hey, we haven't connected here yet. Would love to keep in touch." If they accept, you see everything. If they don’t, you have your answer. No hacking required.
When you click on one of these "FB private profile viewer new" links, here is what actually happens. You will encounter one of three scenarios: fb private profile viewer new
Here is what you need to know about Facebook privacy and these types of tools: The simplest method