England in not very famous for good, sunny weather; as sunny days are kind of rare most people living here seem to celebrate every time we are blessed with a summery afternoon. When that happens on a week end many people, and I mean lots of them, have pick nicks on the various parks and, regularly they leave they rubbish behind. The picture here was taken a couple of Sundays ago, just after a nice Saturday. 
I am appalled by the lack of education and sense of responsibility that many people have but I am also wondering what is Cambridge City Council doing about it? Sending people to clear afterward is a remedy… perhaps having an officer checking that people behave properly and clean after themselves would be a good idea. There are so many traffic wardens around ready to give you a parking ticket, day and night; perhaps a rubbish warden (or park warden) could keep our parks clean by preventing citizens from leaving rubbish around.