Facebook Anonymous Viewer Link

The Truth About "Facebook Anonymous Viewer": Why You Can’t See What You Want (And How to Stay Safe Trying)

If a user has set their profile to "Private" (Friends only), Facebook’s servers will not serve you a single pixel of data unless you are logged into an account that is friends with that user. There is no "backdoor." A website claiming to bypass Facebook’s server-side permissions is lying. They cannot hack Facebook’s database from a simple web interface.

Safer alternatives:

Even if a tool did work, using it enters a gray area. Facebook Anonymous Viewer