It was a very good try, but the police do have a fair point. There is too much stop and search of innocent tourists in the Capital. Recently saw a 'stereotypical' Railway enthusiast being questionned by 4 policemen at Kings Cross!
On the other hand, if caching in the central parks is a bad idea, then maybe lets consider some of the dodgy activities that occur in the outlying parks such as Bushy. I hardly ever see police around there!
He who hesitates is not only lost, but miles from the next exit.
How Many Roads Must A Man Walk Down Before He Admits Hes lost?
Only those who will risk going too far can possibly find out how far one can go. - TS ELLIOT