Someone stole lockbox off my front door!

Glad you noticed before leaving the house or going to bed...
Some people!!!

I just had to post and get my thoughts out...someone stole the lockbox off my front door (am selling house) today!
I heard this thump thump at the door and when I went to go see saw some girl walking back down the sidewalk. I just figured it was one of the many people that put fliers on the door, etc.
So tonight I went out to look around and lo! The lock box was gone. I immediately assumed she cut the box off to get the house key...so I called the police and am still waiting for a locksmith. Can you BELIEVE this? Some people are just rotten...what if I hadn't seen it? They might have come in when I was home and hurt me! I am still shaking a bit, more in anger...will feel better when the locks are changed. The police are patrolling the streets frequently too.
Anyone had this happen???