One thing that I LOATHE about the faction/Hero-vs-Villain format in MU form is the amount of planning that seems to take place on an OOC level. Over the years I've seen a lot of sudden, incredulous coordination that always gives me a raised eyebrow.
- All of the sudden, mid-combat, without any vocal or IC communication, six players unleash a devastating combo attack and they're all ready for it.
- On Lords/Ladies games I've seen elaborate teamwork responses to other PC political actions without any logs or evidence that any of it was planned ICly.
Even when I run tabletop games, I don't allow the players to huddle and discuss OOCly what to do. As a GM, I don't really care what the players know. I don't care if I've got a cop, a pharmacist, a politician, and a computer expert playing the game. This information being used when it isn't on the character sheets(and the ability to network OOCly to coordinate some kind of awesome IC plan) is, in my opinion, metagaming.
So, naturally in the holistic PVP sense, my gamer-brain goes on this sort-of alert status. I think, with this format and all of the paging, skyping, emailing, or other communiques that can be passed under the table, it's simply way too likely that people will coordinate OOCly to win ICly.
WoD games tend to be fucking horrible about this, right on down to PLAYERS browsing the books to put together nigh-indestructible merit/power combinations that the CHARACTER may not have even had the baseline knowledge as to how to achieve. A dropped batch of hot XP in a skill the character has never presented any inclination towards should not turn "pacifist flower girl" into "armored human tank" overnight.
This happens because of OOC planning/knowledge driving the IC.
EDIT: Think "PC HIVE MIND", where what one character knows, all of them know, and although Player A only succeeded in the perception roll, somehow Player B moves their character to be in a good position for when the fight starts. The PLAYER knows a fight is starting, and wants their character to be in a sweet spot.