What do you think of the Sevens' security measures? Several people have complained, through these columns about the apparently heavy-handed way a number of naked/semi-naked pitch invaders were treated on-field at the Hong Kong Rugby Sevens. I don't know what the fuss is about. These yobs deserve a good thrashing. In a fit of drunken bravado they chose to strip off and then make a mad dash across the field for their 15 seconds of fame. Perhaps they would think a little harder if they knew they were going to receive a couple of slaps from some burly official. If I had my way, I would take them straight down to the teams' warm-up area where they could do an hour or two's tackle-bag duty. After that I would send them down to the Wan Chai nick where they could spend a night in the cells. The next morning they should be dragged off to court, fined HK$10,000 and banned for life from the Hong Kong Stadium. They are an absolute disgrace. Mark Cryer, Kennedy Town Have you had any problems with public open space? I am writing in response to the letter from Callan Anderson (Talkback, April 1), regarding the use of public open space at Taikoo Place and the status of Tong Chong Street. In fact Tong Chong Street is privately owned by a wholly-owned subsidiary of Swire Properties, although we do, throughout the year, hold a number of different events all of which are open to members of the public. These events, which have included hosting the Hong Kong Philharmonic Orchestra as well as overseas dance troupes, as part of our work with various youth performing arts groups, necessitate, on occasion, the cordoning off of a section of Tong Chong Street to facilitate setting up the stage, and for rehearsals and performances. However, vehicular access off King's Road into Tong Chong Street is always maintained. We do permit photography in and around Taikoo Place as we have an extensive collection of artwork which we hope is viewed as an enhancement of the overall environment. We apologise if any member of the public, in a dedicated open space, was denied the right to take photographs of either the art pieces or the exteriors of our buildings. Miranda Szeto, head of public affairs, Swire Properties On other matters ... The annual grave-rubbishing festival was in full swing yesterday on Lamma. While I totally respect a culture that seeks to honour its dead and enjoy a day on our hills, I can't understand why it does so by chopping down life-giving trees, failing to follow safety guidelines in the fires it lights and leaving more rubbish behind than it sweeps away. Yesterday morning I watched families leave graves with potentially dangerous fires still burning and grave areas not just strewn with offerings, but also with discarded plastic bottles, pink string and bags. I also noticed how graves on Lamma are getting bigger and bigger, with one person now enjoying far more space in death than life. Concreted areas often extend to more than 700 sq ft per grave, frequently located inappropriately right next to a house on land suitable for a well-designed dwelling. This is not sustainable. At this rate space will fast run out for future generations and our beautiful hills will be scarred forever. A review of grave sizes in rural areas is urgently needed. And environmentally friendly ancestor-worship practices need to be promoted. As people come to understand the damage we humans are wreaking on this world, maybe they will be happy to be remembered with a carbon-absorbing tree or shrub, lovingly tended at Ching Ming and Chung Yung, rather than slabs of concrete and offerings of stacks of papers and their relatives' rubbish. Katherine Cheung, Lamma Patrick Lei, of the Environmental Protection Department, provided good information on plans to properly dispose of fluorescent lights (Talkback, April 2). I would like to ask him if anything similar is going on for small batteries. These batteries are quite terrible polluters, and are used and cast away with great regularity. People are increasingly using rechargeable batteries, but tremendous numbers of the conventional cheaper-to-produce types are thrown away every day. Manufacturers are producing lithium instead of cadmium types but the contents of those are also highly polluting. A collection facility and publicity about their toxicity would be good department projects. It is presumed by interested parties that there are follow-up plans for correct disposal and it is not just another journey to the waste dump for a remix. Tony Henderson, chairman, Humanist Association of Hong Kong Responding to Boyd Boxshall's criticism (Talkback, March 29) of my views on green walls (Talkback, March 27), I would urge Mr Boxshall to reread my letter. It was chiefly concerned with the role of the Urban Renewal Authority (URA) in urban redevelopment. I argued that the URA is trying to use green walls as an architectural gimmick to conceal the authority's deficiencies. The URA hopes that this will encourage others to think that it is doing its job properly, by adopting in its redevelopment plans the latest sustainable design. I do not think this is an acceptable tactic. Green walls are only needed when space for natural greening is limited. Why do we need to engage in a complex vertical planting process and all the associated maintenance hassles if we can create a proper garden? Green walls or vertical planting defies the laws of physics and is unnatural. What we should be doing is urging the government to allow a proper distance between buildings, allow more planting strips and to adopt a 'city in the garden' mindset. From this perspective, the green wall is nothing but an afterthought and is a gimmick. H. C. Bee, Kowloon Tong Janet Wertle (Talkback, April 3) wondered whether any women have objected to the king-sized Calvin Klein advertisement in Central. Quite the reverse. At my workplace, the women are the ones who most appreciate this fascinating addition to the landscape. Eyesore? No way. More like a sight for sore eyes. Pauline Bunce, Chai Wan