On Imperial when you kill someone it says you get nothing as reward but on your cash you can see that you got 1s. However you cant put this 1s into bank, neither invest it ... if you withdraw 1d from the bank the 1s will be gone. You will get an additional 1s every kill (although you practically get nothing).
This also happend when there was the 10s reward (then you had 11s cash on hand).