Also, tourists may ride these cables in Costa Rica, where they are referred to as ziplines.
Looks like they could use new harnesses, clips, and pulleys.
+1 for the YouTube movie link , very illustrative. This is a documentary well worth viewing. I was surprised that the cocaleros remain a good sense of humor despite their dangerous (and subsistent) living style.
As you point out, coca leaves can be processed and refined to make cocaine. Analogous to how corn can be refined into high fructose corn syrup. Chewing corn all day won't give you diabetes, but drinking high-fructose corn syrup regularly will have negative effect on your health.