@JockyB Couldn’t find any details within their current Bylaws John that were that specific? The closest one I could see was the banning of vehicles. Their bylaws also stated the maximum fine imposed for a successful conviction was £50. Interestingly, the same sum of money it cost for them to respond to Simon Hawkins’ FOI request. I doubt they wouldn’t even bother taking anyone to court for such a ‘piddling’ amount. 
Judging by the number of hooligans I’ve seen unchecked riding their mountain bikes through the parks at speed with only one wheel in contact with their sacred grass I doubt they would blink an eye at a quiet bloke in one corner of the park looking at the skies. 