Hobos are a gang in Rumble Mode. They are not an actual gang, just a collection of characters that fit the category.
Hobos are older homeless men who appear frequently throughout the game and they can be found in almost every mission. They can usually be seen digging through trash cans looking for thrown out food or sitting on sidewalks begging for spare change.
In The GameEdit
If the player gives them money, they will give the player information on where to find the nearest flash dealers, knife dealers, and spray dealers. They can eventually be recruited to fight for the player.