Same thing happened to me at the Westin in Seattle.

I came back to the room one afternoon, and found chips all over the entrance. The door was also "cracked" open with the privacy latch holding it open.

I was quite upset. I called hotel management and security, and they couldn't figure out who had left the chips in the room.

Why do hotel staff crack doors open on rooms that have guests belongings in them?? This is one of the main reasons I always end up locking my luggage and taking my vaulables with me even if I leave the room for half an hour...