How do you find the market's/people's needs without talking to them? (let's say for example within the field of programming)

I don't have that kind of access to people for several reasons (long story).

So let's say a guy with a PC and an internet connection. How does he find the needs of the market so he can make a successful product, or to at least find an idea?

Can't go around to people or companies to ask around what their needs are, can't talk to them at all. So how do I find my idea then, how do I do the research that would lead me to an idea?

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