Early in the new year a report is published by US academics warning that eating Scottish farmed salmon potentially causes cancer. The industry erupts in righteous defence. UK scientists are wheeled out whose views refute the US report. UK politicians urge salmon eaters to disregard the warnings and assure us of the product's safety. The Scottish tourist industry worries about the impact on visitors. Salmon farming communities worry about the impact on jobs and local economies. The tabloids run scare stories. Supermarkets put the stuff on BOGOF. A week later and things have calmed down. Then the WHO puts forward its proposals on global diet, physical activity and health hoping to address growing obesity among the world's population - a figure currently standing at more than 3 billion and rising, quite literally. One of their recommendations is that sugar should be limited to a 10% maximum in any food product. The US demurs, saying that their 25% ceiling is perfectly satisfactory, and accuses the WHO of bad science. The fact that the average American daily consumes 34 teaspoonsful of sugar is, they claim, only marginally to blame for Americans' obesity. They fail to add that the $5b US sugar industry gave the Bush campaigns huge political donations out of its $3.5m lobby spend. Then there's another scientist - Prof Sir Roy Meadows. This one seems to have invented a medical condition all of his own - Munchausen's Syndrone by Proxy. Meadows's expertise - his ownership of knowledge - has resulted in upwards of 250 cases being identified as potentially unsafe. Meanwhile thousands more lives have been shattered. Who truly owns all this science? Who can own it? And where, among all these imposed values, all these constrained choices and all the phoney publicness that goes with owning knowledge, is there any space for trust?