That they don't see it does not mean there is no threat (to both their privacy and to their lives in general as secondary effects of the global loss of privacy).
"It is sort of absurd to think what you do online is private."
I find it absurd that you say that. I chat with friends via our own jabber server, for example, via TLS connections - how is it absurd that that is in fact perfectly private? I find neither the expectation of privacy absurd, nor the fact that that is in fact private.
"Your computer might in your bedroom, but the internet certainly isn't."
I don't get what you are trying to say here. Are you just stating the obvious fact that those people who do transport your data technically can look at it, or are you implying that therefore they have the right, they should have the right, that you should have no expectation of them not looking, ...?
Before you answer, please consider: Do you think the same applies to letters? To phone conversations on analog phone lines?