Did you ask a nosy question? Maybe you made an inappropriate comment. These could pertain to procreation, sexuality, gender, diets or weight, etc. Even if you felt like you were in the right, the person who handed you this card, has a different opinion. They would prefer you not to ask or comment on this topic in the future. To them you have overstepped. This might be a one time thing, but maybe it is a common reoccurrence. This card is a simple reminder that, although social media has created a climate of oversharing and voyeurism, in reality not everything is your business. Yes, sometimes we interject when we are worried for our friends' mental or physical safety and health, but in the majority of those cases, you would not receive this card. So, in the future, before you project yourself into someone's personal business, pause and ask if it is really any of your business.