Missing Courtesy

So, all other complaints about my housemates (and there are many, many of them) aside, I have this to say: C is missing.

She has been having a bit of a difficult term, and as such doesn't have any exams this week but has been bumming around anyway. She went away for Thanksgiving last weekend and told us she'd be back on Monday. Fine. I got back Tuesday night and saw, upon my return, that her car is not where it usually is in our driveway. Apparently, nobody has heard from her. I'm glad I wasn't here on Monday or I would have been worrying about her that much longer.
I know she's okay (or at least, she was) because she was on facebook last night, she wrote on someone's wall. Not anyone living in our house, but someone, anyway, so I know she's alive (or at least, was last night.) But I've called her, texted her, written on her and her sister's facebooks, and she hasn't responded. Another one of my housemates, R, has also done these things. C and R aren't best friends, but R gets worried like any normal person.

Now, worried as I am, I'm a little pissed at C. She has methods of communication. She has my and R's facebooks, e-mail addresses, cellphone numbers, etc. She even has my American cell number, she could have called me within the States this weekend to let me know what her plans were. There are also things that still need to be done around the house. I need to pay January rent--C needs to give me a cheque. We also need to return our housekeys in exchange for new ones. C lost hers, so she'll need to pay for it, and clean up loose ends. The people in this house would have been happy to help, but we aren't psychics, you know? I'd think it was just common courtesy to let us know what was going on.

I understand we're nobody's mommies (thank God.) but we do worry. Something could have happened, you know?

Which brings up the question: what caused people to worry before this age of constant communication? (Everything, probably.)