Prying
Overview
Prying (poking into things that are none of your business) is the act of trying to dig into another person's private matters more than necessary. In Japanese, the word is read sensaku. It is used in phrases like "to pry," "nosy," and "I hate being pried into," and it carries the sense not of simply asking a question but of persistently pushing into areas the other person doesn't want to talk about.
Face to face, you can notice "I went too far" by watching the other person's expression and reaction, but in text-based communication, that brake is harder to apply. On anonymous services like question boxes, the sender's identity is unknown, so the bar for prying is thought to drop even further.
Prying in question boxes
"Do you have a boyfriend?" "How much do you make a year?" "Where do you live?" Question boxes sometimes receive probing questions that people would never ask face to face. The feeling that "I can ask because I'm anonymous" can push people toward prying.
Even with a prying question, the sender may just be asking out of pure curiosity. But for the person receiving it, it is unpleasant, and they may feel it as an invasion of privacy. The assumption that "I can ask anything because I'm anonymous" is wrong.
Other ways to say prying, and similar words
Depending on the context, prying can be put in a few other ways. For the act of pushing in itself, there are "fishing for information," "sticking your nose in," and "grilling someone about every detail." For the attitude of the person who pries, there are "rubbernecker," "busybody," and "meddling." For a softer way of saying it, "taking too much interest" or "being very curious" come close.
What people often mix it up with is curiosity. Curiosity is the wish to know itself, and in itself it is neither good nor bad. Prying refers to trying to satisfy that curiosity while ignoring the other person's wishes. Even though both are "asking," it is easier to understand if you sort it out like this: asking about what the other person wants to talk about is conversation, and trying to drag out what they don't want to talk about is prying.
How to deal with prying
There are three ways to deal with prying questions: ignore them, turn them down gently, or show where your boundaries are.
Ignoring is easy, but people may pry further, asking "Why won't you answer?" Turning it down gently ("That's a secret!") is unlikely to cause friction. Showing your boundaries ("I don't answer questions about personal information") is a way of telling people in advance how you'll handle questions of the same kind.
Whichever way you choose, you don't need to force yourself to answer questions you don't want to answer. The question box belongs to the person answering, and there is no obligation to answer every question.