Books gone

I was walking to get the bus to work yesterday and was passing the phone box where I had left the books the day before - they were gone. Just as I was passing, 3 schoolkids were approaching from a side-street and I heard this snippet of conversation:

"....they're not there anymore, they had a sticker on the front saying take me home, I'm free..."

I have checked on-line and no-one has logged them as "caught" yet.