How long has the owner been away? Maybe s/he is ill and no one knows it?

An online friend of mine had a site she'd ran for years. The site had an active community going on both the forum and the blog. Over a two year period my friend began to spend less and less time at her site.

I noticed she'd been away much longer than usual. I asked her if everything was OK, and it turns out, it wasn't. She had cervical cancer. She went in for an operation and the doctor botched things up. She died from complications shortly afterward.

No one even knew until her daughter sent out an email to all of her mom's friends to let them know she'd passed away.