Silently dropping QoS marked packets on the greater Internet

[Jesse McGraw]

  I've recently run into a hard-to-troubleshoot issue where, somewhere 
out in the greater Internet, someone was silently dropping packets from 
my company that happened to be marked with DSCP AF21.  I'd fully expect 
others to either ignore these markings or zero them out but just 
silently dropping them seems unnecessary.

So, how do you guys treat marked packets that come into/through your 
networks?