You can dig deeper past someones personal lives, but make sure you are well-prepared for the unexpected. When you find a dirt somewhere there during your "digging", make sure not to judge them, and of course it is absolutely not a suitable topic for discussions with the peers. You can give advice and shits but make sure you preach using the most polite and suitable method. But, before you let them know, you need to realize some things are better left unsaid.. and have you ever wonder why they hide it in the first place? probably because they just dont want others to know it (and believe me its not a rocket science). It would feel awkward for you dealing with someone who looks so good in front of people when they are actually a psychopath in the inside isnt it? but that is your fault for not minding your own fucking business..
Humanity (you and me included) are not perfect and never will be. Just accept it as it is.