Yeah, I always use that term myself. All asians have a tendency to use that term to describe people as well as themselves, LOL. It's not offensive as long as you really mean it in a harsh way.
Used to describe someone who's foreign, which can be noted by their accent.
I always use it to describe anyone that's Asian with a really bad English accent. It is offensive if you call someone a fob when you don't know them or anything, but it's been used a lot between friends as jokes and stuff. So whether it is offensive or not, it really depends on the context it's used in.
a lot of ppl does that in my city, he just call some asian guy fob and push him around, and he don't even fight back or anything. When someone called me fob and push me around, I pick a fight with them :/