I got to "talk" to them through Randy, who speaks like a native. I didn't ask for a translation of their message, but did learn that they have a three story "institute of grafitti" in ciudad chihuahua, which i hope to visit some day. they had a permit to paint, but it was for another location, and they carry it around with them wherever they go to show anyone who might question them. we saw other murals they had done as well. quite accomplished artists.