Friendly in trouble, dive in to save him, kill the guy who didn't see it coming (or maybe he did but refused to break off).
Enemies call this PICKING, Friendlies call this "Thanks!"
The other side of the coin and more often the case: Picker comes across 1v1 doesn't ask if the friendly needs help, swoops in and picks off the con in one of the usual uber rides and just heads off looking for next pick while thinking about the glory of having his name "landed 5 kills" and 2 seconds of message time for everyone to see.
Some players will hold off, ask if you need help and some like myself will even hold off if I see a 1v1 and unless the friendly asks for help I don't interfere. Nothing is gained by just picking off players other than respective attempt to pad your own score/stats.
Coming across the usual 3-5 cons chasing one friendly, different story generally because the guy is already calling for help before you get there.
Squads are bascially small hordes with better comms and generally play in the same style looking to see what they can overwhelm with numbers and get easy kills. Some squads I have a great raport with and enjoy going up against them for the challange, others I stay clear of as they show little or no respect and aren't worth the time.
There is far more to the game than just gunning for kills as easily as possible, once you reach that stage you'll enjoy ACM side of the game far more, and if you do that from high eny ride the rewards are even greater.
Of course some will cry back take it to DA rant rant rant, been there done that plenty. But at this point in time I might be in MA and a little respect goes a long way.
<S>...-Gixer