Junk Fort Password: bananabeer
-Located in the basement of Junk Fort
Toxic Caves Password: crystal9
-Found by passing through the hills South of Ricardo's Plantation, making it to the end, and entering the cave.

Marvin's Lab Network Password: toadman
-Walk over the planks and turn left once you hit the fork. The lights should stand out in the darkness of the cave
Broken Tooth Pass Password: deathtoghouls
-Located basically at the start of the map, inside of the little hut that Garcia stands in.

Note that there is no password required if you're going through The Scumlands.

All of the Potchutla Terminal passwords will be here, as they're all accessible at once if you know what you're doing.

♥♥♥♥♥♥♥'s Cybernetics Password: mirrorman
-Located in, well, ♥♥♥♥♥♥♥'s Body Shop in the Warehouse District. It's a quick left and right turn if you're approaching from the gate near which Tio stands.
Brillo del Sol Password: sunshine
-It's the giant apartment building in the Market District, pretty hard to miss.
Body Count Bar Password: gotjuice
-It's in the backroom of the Body Count Bar similarly in the Market District. It should stand out distinctly. If it helps, it's right off of Freeway 175.
East Gate Terminal Password: tallwall
-Also near the gate that Tio stands next to.
South Gate Terminal Password: bloodbath
Accessible by killing Gomez, taking the key, and using it on the battlements door in the Southern District. Alternatively, have 50 agility, use red juice/run like hell/muscle flex to just hop up on the railing of the guard post, and parkour your way to the border wall. It's an easy trip down from there.

Potchutla Sewers Password: nomoresecrets
-Go into the sewers, take a left and jump across. The first room on the right will also have another room behind a wooden door. Go in, and there's your terminal.

I don't got anything, this is just the siege. Run, think, shoot, probably die.

Loma Larga Terminal Password: angelina
-In the shack directly opposite of the bar.

Into the jungle, not much to hack here.

Ruins Password: earlyretirement

Polyphonic Terminal Password: albatross
-In the room directly left of the prison cell.
Good luck lol

Nothing much here as well, go kill Bob or Leon or something.

Oil Platform Password: slipperyfish
-Kill biggum on the top, take the key, and use it on the locked door on the third floor. It'll be directly ahead.
Top AARFY Terminal Password: singularity
-Vaguely drop down onto the center platform
Bottom AARFY Terminal Password: singularity
-Below the top one, good luck with McVannon

Truth be told, I don't know how you'd get half of these passwords. Probably through detect motive and asking questions, but I'm too lazy to do that. I had to start digging through the script files when I couldn't find the oil rig platform password, softlocking me.

I hope this helps you, wherever you are in this game.