They're called "burglar bars."
In the movie TRAINING DAY the 3 Mexican guys that were going to kill Denzels partner were like Pachucos....
or as Cheech says *Hey Pendeho's!
To keep out the cholos.
(from the Daily Texican):
"U see a lot of people call me a cholo and frankly i dont think im, so maybe i put a little too much starch on my dickies but thats just the way i waz raized cuz I waz born in los angeles but I got shot twice in a drive by 2 years ago and move to houston with my mom Ive never been in a gang but even though the people at school got me on lockdown asking me about anything that happens and i hate it cuz they be judging me just cuz im brown and my step dad dryves a lolo i hate this pinche gringos so what i mean by this is that if wear starched kakis and drives lowridaz it doesnt mean that u are a cholo im thirteen years old and these people think im gonna jack their cars as soon as they turn around."