QuickTwist
Spiritual "Woo"
Blue roles often play deliberately scummy so that mafia don't NK them. Mafia often NK the people who seem hard to lynch (aka the very Town people) so by appearing scummier than usual a blue role gets off the NK radar and also knows they can either roleclaim and bait a mafia or avoid being lynched themselves.
It's a fine line to tread to be not targeted by either the Town or Mafia.
That may work in theory, acting scummy on purpose, but it doesn't work so when in an actual game. Its just an unnecessarily risky strategy that could get you lynched. Things can snowball rather quickly so you really have no control on if you get lynched by playing scummy on purpose.. I mean what would you do to accomplish this? Think about it, if everyone acts townie it gives a smaller chance that you will be NKed. That's why town should act like town. Granted, sometimes its good for PR to vary their style so they don't get NKed or lynched but playing scummy on purpose is not a viable option.
I talked to the first place winner of the 2015 Mafia Championships about optimal Cop strategy and they basically said you should play just as any other VT in terms of Scummyness.