Good Questions

I noticed today that my office building is flying the American flag at half mast. My guess is that this is for all those that died in the tsunami. But I realized I don't know if it's for all the people that died in the tsunami or just the Americans. What is the policy on flying flags at half mast? I thought it could only be flown at half mast for soldiers. Can it be flown at half mast for anyone? Do they have to be American?

What if my hamster dies, can I fly my flag at half mast then? (Assume for a second that I actually had a hamster at one point.) Or what about my house plant? If I forget to water one for a while, can I fly my flag at half mast? Or suppose I run over a squirrel on my way to work, does that count? What about the turkey sandwich I had for lunch, does that count?

Now, suppose my flag is the Jolly Roger. Can I only fly it at half mast when Johnny Depp dies?