I would agree with you mummoonin if I also thought my child was "upset, alone and in danger". But I didn't and don't.
a) he always slept through within minutes of being put down (yes, I know we were very lucky). Even if he had woken up, he was never bothered by new or different environments - which I can assert by his reaction on waking up in the mornings. So he wasn't upset.
b) he was no more "alone" than he would have been at home: indeed, he was checked on every half hour - which is more than he would have been done at home. SO I don't consdier he was "alone" - anyomre than he would have been at night at home.
c) I disagree about him being in danger - which I know we won't agree on. I refuse to live a life fearing that everyone you come across is dangerous. I prefer to beleive that most people are good and to trust them. And guess what - most people are good! As cestlavie (I think) has already pointed out - the statisitcs are that most accidents and injuries happen in the home. So I don't conder he was in danger.
I've already told the story of ds being whicked away frome our table one lunchtime and being entertained, a large part of it out of our sight, by the staff at a resturaunt in SOuth Africa. I didn't know these people from Adam - they could have been kidnapping him for all we knew. However, instead it was a wonderful experience for him (unfortunately not one he will remember as he was too young) and the sort of thing that I am sure has contributed to him being the confident, indepedent wee boy he is today.
It's moving on to another topic, but we had a argument disucssion with someone while we were on holiday in Greece (in that hotel where ds sleeps in the room a few yards away ) where they said "surely you would want to know that your ds' rugby coach was CRB checked" and dh answered "no" - what was more important was that we knew the coaches involved, were involved with both the club and the children - and that ds knew whar was acceptable and unacceptable behaviour. And nay, the CRB check is only as good as the time it was done - and whether anything has been reported/convicted.
I had a discussion with my dad a wee while ago and the current "parent blame" culture and the fact that we some people are scared to allow kids to do what we used to be able to do without question. He pointed out that the difference now is that in the past, if, for example, a child got knocked over walking to the shops to do an errand - or even walking to school, it would have been the driver that was blamed. Today it would be the parents that would be blamed for having let the child out.