Here's one I discovered last night:
Sorry to those of you that sent me either an invite, or put up Lobby in a message in an attempt to get an invite. Last night I was playing offline, split screen co-op with a neighbor and I guess the online, in game, friends list was showing me there even though I had never crossed into online mode in the game.
Just thought I would share this experience so you all aren’t mad at me maybe thinking I was ignoring you, and we now know just because someone’s name is there doesn’t mean they are actually online.
I sent a few messages out to a few members letting them know what was going on.