Bear in mind that wild camping in England is still technically illegal, and to avoid a knock on your tentpole in the middle of the night ( the worst thing that can happen is you'll be asked to move, but who wants to have to break camp and move on in the dead of night ? ), follow the wildcamping rules :-
Arrive late, preferably at dusk
Leave early
Leave no sign
No open fires
Don't make too much noise - sound travels well across quiet moorland at night
If you need to take a dump do it well away from any areas frequented by walkers, and bury it well
I've wild camped in the Peak District, Lake District and Snowdonia, and have never had any problems. I know people who have however, and usually its because they've broken 1 or more of the above "rules" and attracted attention to themselves.
Remember - if no one knows you're there they're not gonna mind you camping . . .