The latest from the Guardian makes it clear why many Afghans don't support the US occupation:
Twelve American soldiers face charges over a secret "kill team" that allegedly blew up and shot Afghan civilians at random and collected their fingers as trophies.
What's embarassing about this is that they weren't caught by somebody turning them in for that. Instead, they were caught because they beat up another soldier for turning them in for doing drugs in his bunk:
The soldier, who was straight out of basic training and has not been named, said he witnessed the smoking of hashish and drinking of smuggled alcohol but initially did not report it out of loyalty to his comrades. But when he returned from an assignment at an army headquarters and discovered soldiers using the shipping container in which he was billeted to smoke hashish he reported it.
Two days later members of his platoon, including Gibbs and Morlock, accused him of "snitching", gave him a beating and told him to keep his mouth shut. The soldier reported the beating and threats to his officers and then told investigators what he knew of the "kill team".
This means that there are doubtless other, better mannered finger collectors, running wild in Afghanistan. And it doesn't take many to make the Taliban look good by comparison.