I was at a house party once, asleep on the lounge floor alone downstairs on an airbed. My bag and that of a friend was taken from right by me in the night, phones, purses, everything. When we rang the phones these kids were answering!
I had a very hard time trying to sort out my phone insurance as I couldn't guarantee whether the house doors had been locked, as it turned out, probably not as no signs of a break in. I guess something I didn't think about with it not being my house, to my cost.