Saying "sorry" via Facebook

Yesterday morning when I got into the office (having walked through the crowds in Martin Place) I made my own personal 'sorry' declaration on Facebook via Twitter (I appreciate doing that achieves nothing in a practical sense but yesterday was all about the symbolism, right?).
When I next checked back at the end of the day I found lot of my friends had done the same. I can't recall having seen that happen before and I thought it was an interesting outcome of on-line social networks. I wondered how many others did the same.
Perhaps in the future we'll no longer need to ask our friends the 'where were you on that the day X happened?' question around significant events -- because we'll already know.
Update: Looks like Chloe Lake over at News had the same idea.
Update 2: Here's an interesting counterpoint: Radio callers outraged: I'm disgusted, says one. My reading of on-line opinion (after all blogs etc are now another way people share their views en-mass, talk back radio is no longer alone there) suggests many were supportive.