How do you give GMing advice to a friend without upsetting them?  is an entertaining RPGnet  thread about the age-old dilemma of giving criticism to your friends.
There’s some good advice in there, and I’d have linked to it solely on that basis — but the clincher was that the GM in question (who needs the criticism) smokes pot while he GMs.
Eeeenteresting. Is it just me, or is that a spectacularly bad idea?