This policy is relatively complex with 7 statements. They detail a typical 
company access hierarchy where everyone can list specified folders, but 
can only perform other s3 actions in a shared folder or the user's own 
folder. The policy uses conditions, some with multiple keys and some with 
multiple key values. 

source = https://forums.aws.amazon.com/thread.jspa?threadID=275918&tstart=425
