“Funyuns, son get your fiber!” Holder to Jack (1x2), as they talk about whether Jack and ‘Sonoma’ get along. /
“His password is funyuns.” Holder to Linden, searching for Jack (1x11)
I didn’t notice this till my second watch of The Killing, but I think that Jack set his password this way because of Holder (influence / Jack looks up to him). It shows how important Holder is to Linden’s son, in a subtle, great detail.