“in the internet” and “on the internet”
Why do we say "on the Internet" but not "in the Internet"?
This seems to be against the meaning of these prepositions.
I'd think it's a carryover from the phrase "online" (or "on line"). Which in turn probably goes back to "on the phone." And in that last one, "in" wouldn't make sense.
When talking about information that's on the internet: preposition "on" is used for information that is disseminated by certain media "on the television", "on the radio", "on the grapevine" and therefore by analogy "on the internet".
When talking about someone being on the net: this is perhaps more akin to being "on the telephone".
It's hard to give reasons why something isn't done, but I'd say that we don't use "in" in these cases because that conjures up a spatial image, and the internet isn't really a place.