If a profile is private or locked, Facebook strictly limits what non-friends can see:
Some sites ask you to download a program or install a browser extension. These often contain keyloggers, adware, or remote access trojans (RATs). Hackers can then steal your saved passwords, browser history, and personal files. facebook private profile picture viewer online 2021
Facebook processes privacy permissions on its own servers. If an account is restricted, the server does not send the full-resolution image data to an unauthenticated or unauthorized browser request. Third-party websites cannot force Facebook's servers to deliver restricted data without a legitimate exploit. If a profile is private or locked, Facebook
: Some ask for your own Facebook credentials to "verify" you, which allows hackers to take over your account. facebook private profile picture viewer online 2021