In reply to GrahamD:
Yes, being a bit flippant there.
Most of what is have said is true - apart from the secluded bit. You might get away with bivvying below Fandango Wall if you rocked up in the dark and were very very quiet, but not with a fire!
But then you might actually be woken up by groups in the night doing various team building type activities.
To be fair, we dossed at Bowles many years ago on the way to the continent and did get away with it.