hi ian, those are very good points you make;
it's not so much turning a blind eye though. one of the main problems for many public service workers on ibiza (taxis, police, firemen, binmen) is that there is too much work for 3 months of the year and not enough for the other 9 months of the year. obviously you can't just employ a policeman on a 3 month contract. which means there are most probably slightly too many police in winter and not nearly enough in summer. the same applies to taxis, fireman, etc.
what you suggest about the clubs enforcing security in the vicinity and of course inside the venue itself, makes really good sense. but even then, with the crowds in high season, especially in space/amnesia/dc10, you'd have to employ so many extra people to ensure the club and surrounding area was free of criminals - a bit like the boy with his finger in the dyke. i am not trying to be negative though, i think it's an excellent idea and an increased security presence would certainly help lots.