So ... I think on Twitter you use @ to tag people in your tweets.
"At the concert with @Joe Blow"
So Joe Blow will be notified that I mentioned him.
But I've also seen people on Facebook, in a thread, use "@" to seemingly just speak directly to someone.
"@ Joe Blow that's hilarious."
Which seems no easier than typing a "," after the name as one would in, oh I don't know, English.
"Joe Blow, that's hilarious."
Or is Facebook tagging names to. Come to think of it I have received "you've been tagged in a note by" notifications, but I don't think I see "@" when I go to those notes, which leads me to think that note tagging on FB os a separate process and people are just using "@" to direct address each other.
hmmm ...