I remember reading a comment a while ago (on Reddit, ironically) which pointed out that SFW subreddits naming themselves [subject]porn are borrowing the wrong part from the word “pornography”. “Porn” is from greek pornē meaning “prostitute”, but the suffix -graphy means “to write” and is often used to indicate “the study of” the thing it’s attached to (e.g. geography, cryptography, demography, etc.)

It would be more accurate, and perhaps less controversial, if these communities named themselves earthography, spaceography, unixograpy, etc. As an added bonus, the -grapy suffix is also prominent in “photography” which is appropriate considering that many of these communities are places where people share photos of the subject matter.