It’s just like any other forum. If it isn’t currently in your streak (check your streak subtab), you can pwn it for your streak. If it’s in your streak, pwning it will reset your streak. If the time when you pwned it for the plot is still in your streak, you shouldn’t re-pwn it. If your streak has been reset since you pwned it for the plot, it’s A-OK to pwn it again. The fact that the previous pwning was for the plot changes nothing; pwnage is pwnage.