Sarcasti-chat
Having an online chat with someone that would be considered rude, nasty or mean if it were in person or overheard by strangers or the people who are being spoken about, but the buffer of being online softens it. Frequently bitchy, catty or petty, it is nevertheless entertaining as hell to the participants, who wonder why they are never this funny when they are in the same room.
"I wonder if their ears are burning? I just got done having a particularly good sarcasti-chat with Carlo on Facebook, where we trashed everyone we knew. I haven't laughed that much in ages. I'm TERRIBLE."