They may force you to complete endless surveys, collecting your personal data, only to give you nothing in return.
If a user has "Locked" their profile, you can only see their profile picture, cover photo, and a tiny fraction of information.
I understand you're looking for information on how to view private photos on Facebook without being friends. However, I must emphasize that attempting to access someone's private content without their permission is a serious invasion of their privacy and can be against Facebook's terms of service.
or is it a casual check of someone else?
Facebook allows users to control who can see their content by adjusting their privacy settings. Posts and photos can be shared with the public, friends, or specific groups. To view publicly available information, it's essential to understand these settings.