People are misunderstanding the rules and always have done! Not helped by the fact that heads often say "if you want your child to come here you need to put it as first preference". What they actually mean is "if this school is genuinely your first preference put it first, otherwise you might be allocated the one you actually put first". My hunch is that there is also some element of bragging rights amoungst head teachers about who had the most first preferences, but maybe that's just me being cynical.
You can refer the school gate gossipers to
this document. It has been illegal for some years for the schools to know where you placed them on the form, but still the rumours persist.